Organic electroluminescent materials and devices

ABSTRACT

A composition of materials including a first compound having a structure according to Formula I

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent application Ser. No. 14/734,712 which is a non-provisional of U.S. Patent Application Ser. No. 62/022,300, filed Jul. 9, 2014, U.S. Patent Application Ser. No. 62/038,925, filed Aug. 19, 2014; U.S. Patent Application Ser. No. 62/060,192, filed Oct. 6, 2014; and U.S. Patent Application Ser. No. 62/083,490, filed Nov. 24, 2014, the entire contents of which is incorporated herein by reference.

PARTIES TO A JOINT RESEARCH AGREEMENT

The claimed invention was made by, on behalf of, and/or in connection with one or more of the following parties to a joint university corporation research agreement: Regents of the University of Michigan, Princeton University, University of Southern California, and the Universal Display Corporation. The agreement was in effect on and before the date the claimed invention was made, and the claimed invention was made as a result of activities undertaken within the scope of the agreement.

FIELD

The present invention relates to compounds for use as hosts, blocking materials, and electron transporting materials, and devices, such as organic light emitting diodes, including the same.

BACKGROUND

Opto-electronic devices that make use of organic materials are becoming increasingly desirable for a number of reasons. Many of the materials used to make such devices are relatively inexpensive, so organic opto-electronic devices have the potential for cost advantages over inorganic devices. In addition, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications such as fabrication on a flexible substrate. Examples of organic opto-electronic devices include organic light emitting devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, the organic materials may have performance advantages over conventional materials. For example, the wavelength at which an organic emissive layer emits light may generally be readily tuned with appropriate dopants.

OLEDs make use of thin organic films that emit light when voltage is applied across the device. OLEDs are becoming an increasingly interesting technology for use in applications such as flat panel displays, illumination, and backlighting. Several OLED materials and configurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety.

One application for phosphorescent emissive molecules is a full color display. Industry standards for such a display call for pixels adapted to emit particular colors, referred to as “saturated” colors. In particular, these standards call for saturated red, green, and blue pixels. Color may be measured using CIE coordinates, which are well known to the art.

One example of a green emissive molecule is tris(2-phenylpyridine) iridium, denoted Ir(ppy)₃, which has the following structure:

In this, and later figures herein, we depict the dative bond from nitrogen to metal (here, Ir) as a straight line.

As used herein, the term “organic” includes polymeric materials as well as small molecule organic materials that may be used to fabricate organic opto-electronic devices. “Small molecule” refers to any organic material that is not a polymer, and “small molecules” may actually be quite large. Small molecules may include repeat units in some circumstances. For example, using a long chain alkyl group as a substituent does not remove a molecule from the “small molecule” class. Small molecules may also be incorporated into polymers, for example as a pendent group on a polymer backbone or as a part of the backbone. Small molecules may also serve as the core moiety of a dendrimer, which consists of a series of chemical shells built on the core moiety. The core moiety of a dendrimer may be a fluorescent or phosphorescent small molecule emitter. A dendrimer may be a “small molecule,” and it is believed that all dendrimers currently used in the field of OLEDs are small molecules.

As used herein, “top” means furthest away from the substrate, while “bottom” means closest to the substrate. Where a first layer is described as “disposed over” a second layer, the first layer is disposed further away from substrate. There may be other layers between the first and second layer, unless it is specified that the first layer is “in contact with” the second layer. For example, a cathode may be described as “disposed over” an anode, even though there are various organic layers in between.

As used herein, “solution processible” means capable of being dissolved, dispersed, or transported in and/or deposited from a liquid medium, either in solution or suspension form.

A ligand may be referred to as “photoactive” when it is believed that the ligand directly contributes to the photoactive properties of an emissive material. A ligand may be referred to as “ancillary” when it is believed that the ligand does not contribute to the photoactive properties of an emissive material, although an ancillary ligand may alter the properties of a photoactive ligand.

As used herein, and as would be generally understood by one skilled in the art, a first “Highest Occupied Molecular Orbital” (HOMO) or “Lowest Unoccupied Molecular Orbital” (LUMO) energy level is “greater than” or “higher than” a second HOMO or LUMO energy level if the first energy level is closer to the vacuum energy level. Since ionization potentials (IP) are measured as a negative energy relative to a vacuum level, a higher HOMO energy level corresponds to an IP having a smaller absolute value (an IP that is less negative). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) having a smaller absolute value (an EA that is less negative). On a conventional energy level diagram, with the vacuum level at the top, the LUMO energy level of a material is higher than the HOMO energy level of the same material. A “higher” HOMO or LUMO energy level appears closer to the top of such a diagram than a “lower” HOMO or LUMO energy level.

As used herein, and as would be generally understood by one skilled in the art, a first work function is “greater than” or “higher than” a second work function if the first work function has a higher absolute value. Because work functions are generally measured as negative numbers relative to vacuum level, this means that a “higher” work function is more negative. On a conventional energy level diagram, with the vacuum level at the top, a “higher” work function is illustrated as further away from the vacuum level in the downward direction. Thus, the definitions of HOMO and LUMO energy levels follow a different convention than work functions.

More details on OLEDs, and the definitions described above, can be found in U.S. Pat. No. 7,279,704, which is incorporated herein by reference in its entirety.

SUMMARY

According to one embodiment, a composition of materials comprising a first compound having a structure according to Formula I

is disclosed. In Formula I, G¹ is selected from the group consisting of dibenzofuran, dibenzothiophene, dibenzoselenophene, and fluorene. L¹ is selected from the group consisting of phenyl, biphenyl, terphenyl, pyridine, pyrimidine, and combinations thereof. L² and L³ are each independently selected from the group consisting of a direct bond, phenyl, biphenyl, terphenyl, pyridine, pyrimidine, and combinations thereof. G⁴ is selected from the group consisting of phenyl, biphenyl, terphenyl, naphthalene, phenanthrene, pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, phenanthroline, and combinations thereof. G², G³, and G⁵ are each independently selected from the group consisting of phenyl, biphenyl, terphenyl, fluorene, naphthalene, phenanthrene, pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, phenanthroline, aza-fluorene, and combinations thereof. G², G³, G⁴, and G⁵ are each optionally further substituted with one or more unfused substituents selected from the group consisting of deuterium, alkyl, alkoxyl, cycloalkyl, cycloalkoxyl, halogen, nitro, nitrile, silyl, phenyl, biphenyl, terphenyl, pyridine, and combinations thereof. m is an integer from 0 to 7. n is an integer from 1 to 4. When m or n is larger than 1, each G⁴ or G⁵ can be same or different.

According to another embodiment of the present disclosure, a composition of materials comprising a first compound having a structure of:

Formula III, is also provided. In the structure of Formula III, L^(A) and L^(B) are selected from a group consisting of direct bond, phenyl, biphenyl, pyridine, and combinations thereof; G^(A) and G^(B) are selected from a group consisting of phenyl, biphenyl, pyridine, dibenzothiophene, dibenzofuran, dibenzoselenophene, and fluorene; and G^(A) and G^(B) are each optionally further substituted with one or more unfused substituents selected from the group consisting of deuterium, alkyl, alkoxyl, cycloalkyl, cycloalkoxyl, halogen, nitro, nitrile, silyl, phenyl, biphenyl, terphenyl, pyridine, and combinations thereof.

According to another aspect of the present disclosure, a device that includes one or more organic light emitting devices is also provided. At least one of the one or more organic light emitting devices can include an anode, a cathode, and an organic layer, disposed between the anode and the cathode. The organic layer can include a composition comprising a compound according to a structure of Formula I or Formula III, or any of the variations thereof described herein.

In yet another aspect of the present disclosure, a method for fabricating an organic light emitting device is provided. The organic light emitting device can include a first electrode, a second electrode, and a first organic layer disposed between the first electrode and the second electrode, where the first organic layer comprises a first composition comprising a mixture of a first compound and a second compound.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an organic light emitting device.

FIG. 2 shows an inverted organic light emitting device that does not have a separate electron transport layer.

FIG. 3 shows Formula I as disclosed herein.

FIG. 4 shows Formula II as disclosed herein.

FIG. 5 shows Formula III as disclosed herein.

FIG. 6 shows Formula IV as disclosed herein.

DETAILED DESCRIPTION

Generally, an OLED comprises at least one organic layer disposed between and electrically connected to an anode and a cathode. When a current is applied, the anode injects holes and the cathode injects electrons into the organic layer(s). The injected holes and electrons each migrate toward the oppositely charged electrode. When an electron and hole localize on the same molecule, an “exciton,” which is a localized electron-hole pair having an excited energy state, is formed. Light is emitted when the exciton relaxes via a photoemissive mechanism. In some cases, the exciton may be localized on an excimer or an exciplex. Non-radiative mechanisms, such as thermal relaxation, may also occur, but are generally considered undesirable.

The initial OLEDs used emissive molecules that emitted light from their singlet states (“fluorescence”) as disclosed, for example, in U.S. Pat. No. 4,769,292, which is incorporated by reference in its entirety. Fluorescent emission generally occurs in a time frame of less than 10 nanoseconds.

More recently, OLEDs having emissive materials that emit light from triplet states (“phosphorescence”) have been demonstrated. Baldo et al., “Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices,” Nature, vol. 395, 151-154, 1998; (“Baldo-I”) and Baldo et al., “Very high-efficiency green organic light-emitting devices based on electrophosphorescence,” Appl. Phys. Lett., vol. 75, No. 3, 4-6 (1999) (“Baldo-II”), which are incorporated by reference in their entireties. Phosphorescence is described in more detail in U.S. Pat. No. 7,279,704 at cols. 5-6, which are incorporated by reference.

FIG. 1 shows an organic light emitting device 100. The figures are not necessarily drawn to scale. Device 100 may include a substrate 110, an anode 115, a hole injection layer 120, a hole transport layer 125, an electron blocking layer 130, an emissive layer 135, a hole blocking layer 140, an electron transport layer 145, an electron injection layer 150, a protective layer 155, a cathode 160, and a barrier layer 170. Cathode 160 is a compound cathode having a first conductive layer 162 and a second conductive layer 164. Device 100 may be fabricated by depositing the layers described, in order. The properties and functions of these various layers, as well as example materials, are described in more detail in U.S. Pat. No. 7,279,704 at cols. 6-10, which are incorporated by reference.

More examples for each of these layers are available. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Pat. No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F₄-TCNQ at a molar ratio of 50:1, as disclosed in U.S. Patent Application Publication No. 2003/0230980, which is incorporated by reference in its entirety. Examples of emissive and host materials are disclosed in U.S. Pat. No. 6,303,238 to Thompson et al., which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1:1, as disclosed in U.S. Patent Application Publication No. 2003/0230980, which is incorporated by reference in its entirety. U.S. Pat. Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entireties, disclose examples of cathodes including compound cathodes having a thin layer of metal such as Mg:Ag with an overlying transparent, electrically-conductive, sputter-deposited ITO layer. The theory and use of blocking layers is described in more detail in U.S. Pat. No. 6,097,147 and U.S. Patent Application Publication No. 2003/0230980, which are incorporated by reference in their entireties. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004/0174116, which is incorporated by reference in its entirety. A description of protective layers may be found in U.S. Patent Application Publication No. 2004/0174116, which is incorporated by reference in its entirety.

FIG. 2 shows an inverted OLED 200. The device includes a substrate 210, a cathode 215, an emissive layer 220, a hole transport layer 225, and an anode 230. Device 200 may be fabricated by depositing the layers described, in order. Because the most common OLED configuration has a cathode disposed over the anode, and device 200 has cathode 215 disposed under anode 230, device 200 may be referred to as an “inverted” OLED. Materials similar to those described with respect to device 100 may be used in the corresponding layers of device 200. FIG. 2 provides one example of how some layers may be omitted from the structure of device 100.

The simple layered structure illustrated in FIGS. 1 and 2 is provided by way of non-limiting example, and it is understood that embodiments of the invention may be used in connection with a wide variety of other structures. The specific materials and structures described are exemplary in nature, and other materials and structures may be used. Functional OLEDs may be achieved by combining the various layers described in different ways, or layers may be omitted entirely, based on design, performance, and cost factors. Other layers not specifically described may also be included. Materials other than those specifically described may be used. Although many of the examples provided herein describe various layers as comprising a single material, it is understood that combinations of materials, such as a mixture of host and dopant, or more generally a mixture, may be used. Also, the layers may have various sublayers. The names given to the various layers herein are not intended to be strictly limiting. For example, in device 200, hole transport layer 225 transports holes and injects holes into emissive layer 220, and may be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED may be described as having an “organic layer” disposed between a cathode and an anode. This organic layer may comprise a single layer, or may further comprise multiple layers of different organic materials as described, for example, with respect to FIGS. 1 and 2.

Structures and materials not specifically described may also be used, such as OLEDs comprised of polymeric materials (PLEDs) such as disclosed in U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of further example, OLEDs having a single organic layer may be used. OLEDs may be stacked, for example as described in U.S. Pat. No. 5,707,745 to Forrest et al, which is incorporated by reference in its entirety. The OLED structure may deviate from the simple layered structure illustrated in FIGS. 1 and 2. For example, the substrate may include an angled reflective surface to improve out-coupling, such as a mesa structure as described in U.S. Pat. No. 6,091,195 to Forrest et al., and/or a pit structure as described in U.S. Pat. No. 5,834,893 to Bulovic et al., which are incorporated by reference in their entireties.

Unless otherwise specified, any of the layers of the various embodiments may be deposited by any suitable method. For the organic layers, preferred methods include thermal evaporation, ink-jet, such as described in U.S. Pat. Nos. 6,013,982 and 6,087,196, which are incorporated by reference in their entireties, organic vapor phase deposition (OVPD), such as described in U.S. Pat. No. 6,337,102 to Forrest et al., which is incorporated by reference in its entirety, and deposition by organic vapor jet printing (OVJP), such as described in U.S. Pat. No. 7,431,968, which is incorporated by reference in its entirety. Other suitable deposition methods include spin coating and other solution based processes. Solution based processes are preferably carried out in nitrogen or an inert atmosphere. For the other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding such as described in U.S. Pat. Nos. 6,294,398 and 6,468,819, which are incorporated by reference in their entireties, and patterning associated with some of the deposition methods such as ink-jet and OVJD. Other methods may also be used. The materials to be deposited may be modified to make them compatible with a particular deposition method. For example, substituents such as alkyl and aryl groups, branched or unbranched, and preferably containing at least 3 carbons, may be used in small molecules to enhance their ability to undergo solution processing. Substituents having 20 carbons or more may be used, and 3-20 carbons is a preferred range. Materials with asymmetric structures may have better solution processibility than those having symmetric structures, because asymmetric materials may have a lower tendency to recrystallize. Dendrimer substituents may be used to enhance the ability of small molecules to undergo solution processing.

Devices fabricated in accordance with embodiments of the present invention may further optionally comprise a barrier layer. One purpose of the barrier layer is to protect the electrodes and organic layers from damaging exposure to harmful species in the environment including moisture, vapor and/or gases, etc. The barrier layer may be deposited over, under or next to a substrate, an electrode, or over any other parts of a device including an edge. The barrier layer may comprise a single layer, or multiple layers. The barrier layer may be formed by various known chemical vapor deposition techniques and may include compositions having a single phase as well as compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may incorporate an inorganic or an organic compound or both. The preferred barrier layer comprises a mixture of a polymeric material and a non-polymeric material as described in U.S. Pat. No. 7,968,146, PCT Pat. Application Nos. PCT/US2007/023098 and PCT/US2009/042829, which are herein incorporated by reference in their entireties. To be considered a “mixture”, the aforesaid polymeric and non-polymeric materials comprising the barrier layer should be deposited under the same reaction conditions and/or at the same time. The weight ratio of polymeric to non-polymeric material may be in the range of 95:5 to 5:95. The polymeric material and the non-polymeric material may be created from the same precursor material. In one example, the mixture of a polymeric material and a non-polymeric material consists essentially of polymeric silicon and inorganic silicon.

Devices fabricated in accordance with embodiments of the invention can be incorporated into a wide variety of electronic component modules (or units) that can be incorporated into a variety of electronic products or intermediate components. Examples of such electronic products or intermediate components include display screens, lighting devices such as discrete light source devices or lighting panels, etc. that can be utilized by the end-user product manufacturers. Such electronic component modules can optionally include the driving electronics and/or power source(s). Devices fabricated in accordance with embodiments of the invention can be incorporated into a wide variety of consumer products that have one or more of the electronic component modules (or units) incorporated therein. Such consumer products would include any kind of products that include one or more light source(s) and/or one or more of some type of visual displays. Some examples of such consumer products include flat panel displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior illumination and/or signaling, heads-up displays, fully or partially transparent displays, flexible displays, laser printers, telephones, cell phones, tablets, phablets, personal digital assistants (PDAs), laptop computers, digital cameras, camcorders, viewfinders, micro-displays, 3-D displays, vehicles, a large area wall, theater or stadium screen, or a sign. Various control mechanisms may be used to control devices fabricated in accordance with the present invention, including passive matrix and active matrix. Many of the devices are intended for use in a temperature range comfortable to humans, such as 18 degrees C. to 30 degrees C., and more preferably at room temperature (20-25 degrees C.), but could be used outside this temperature range, for example, from −40 degree C. to +80 degree C.

The materials and structures described herein may have applications in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors may employ the materials and structures. More generally, organic devices, such as organic transistors, may employ the materials and structures.

The term “halo,” “halogen,” or “halide” as used herein includes fluorine, chlorine, bromine, and iodine.

The term “alkyl” as used herein contemplates both straight and branched chain alkyl radicals. Preferred alkyl groups are those containing from one to fifteen carbon atoms and includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, and the like. Additionally, the alkyl group may be optionally substituted.

The term “cycloalkyl” as used herein contemplates cyclic alkyl radicals. Preferred cycloalkyl groups are those containing 3 to 7 carbon atoms and includes cyclopropyl, cyclopentyl, cyclohexyl, and the like. Additionally, the cycloalkyl group may be optionally substituted.

The term “alkenyl” as used herein contemplates both straight and branched chain alkene radicals. Preferred alkenyl groups are those containing two to fifteen carbon atoms. Additionally, the alkenyl group may be optionally substituted.

The term “alkynyl” as used herein contemplates both straight and branched chain alkyne radicals. Preferred alkynyl groups are those containing two to fifteen carbon atoms. Additionally, the alkynyl group may be optionally substituted.

The terms “aralkyl” or “arylalkyl” as used herein are used interchangeably and contemplate an alkyl group that has as a substituent an aromatic group. Additionally, the aralkyl group may be optionally substituted.

The term “heterocyclic group” as used herein contemplates aromatic and non-aromatic cyclic radicals. Hetero-aromatic cyclic radicals also means heteroaryl. Preferred hetero-non-aromatic cyclic groups are those containing 3 or 7 ring atoms which includes at least one hetero atom, and includes cyclic amines such as morpholino, piperdino, pyrrolidino, and the like, and cyclic ethers, such as tetrahydrofuran, tetrahydropyran, and the like. Additionally, the heterocyclic group may be optionally substituted.

The term “aryl” or “aromatic group” as used herein contemplates single-ring groups and polycyclic ring systems. The polycyclic rings may have two or more rings in which two carbons are common to two adjoining rings (the rings are “fused”) wherein at least one of the rings is aromatic, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryl, heterocycles, and/or heteroaryls. Additionally, the aryl group may be optionally substituted.

The term “heteroaryl” as used herein contemplates single-ring hetero-aromatic groups that may include from one to three heteroatoms, for example, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, pyrazole, pyridine, pyrazine and pyrimidine, and the like. The term heteroaryl also includes polycyclic hetero-aromatic systems having two or more rings in which two atoms are common to two adjoining rings (the rings are “fused”) wherein at least one of the rings is a heteroaryl, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryl, heterocycles, and/or heteroaryls. Additionally, the heteroaryl group may be optionally substituted.

The alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, heterocyclic group, aryl, and heteroaryl may be optionally substituted with one or more substituents selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

As used herein, “substituted” indicates that a substituent other than H is bonded to the relevant position, such as carbon. Thus, for example, where R¹ is mono-substituted, then one R¹ must be other than H. Similarly, where R¹ is di-substituted, then two of R¹ must be other than H. Similarly, where R¹ is unsubstituted, R¹ is hydrogen for all available positions.

The “aza” designation in the fragments described herein, i.e. aza-dibenzofuran, aza-dibenzothiophene, etc. means that one or more of the C—H groups in the respective fragment can be replaced by a nitrogen atom, for example, and without any limitation, azatriphenylene encompasses both dibenzo[fh]quinoxaline and dibenzo[fh]quinoline. One of ordinary skill in the art can readily envision other nitrogen analogs of the aza-derivatives described above, and all such analogs are intended to be encompassed by the terms as set forth herein.

It is to be understood that when a molecular fragment is described as being a substituent or otherwise attached to another moiety, its name may be written as if it were a fragment (e.g. phenyl, phenylene, naphthyl, dibenzofuryl) or as if it were the whole molecule (e.g. benzene, naphthalene, dibenzofuran). As used herein, these different ways of designating a substituent or attached fragment are considered to be equivalent.

Often, the emissive layer (EML) of OLED devices exhibiting good lifetime and efficiency requires more than two components (e.g. 3 or 4 components). Fabricating such EMLs using vacuum thermal evaporation (VTE) process then requires evaporating 3 or 4 evaporation source materials in separate VTE sublimation crucibles, which is very complicated and costly compared to a standard two-component EML with a single host and an emitter, which requires only two evaporation sources.

Premixing two or more materials and evaporating them from one VTE sublimation crucible can reduce the complexity of the fabrication process. However, the co-evaporation must be stable and produce an evaporated film having a composition that remains constant through the evaporation process. Variations in the film's composition may adversely affect the device performance. In order to obtain a stable co-evaporation from a mixture of compounds under vacuum, one would assume that the materials must have the same evaporation temperature under the same condition. However, this may not be the only parameter one has to consider. When two compounds are mixed together, they may interact with each other and the evaporation property of the mixture may differ from their individual properties. On the other hand, materials with slightly different evaporation temperatures may form a stable co-evaporation mixture. Therefore, it is extremely difficult to achieve a stable co-evaporation mixture. So far, there have been very few stable co-evaporation mixture examples. “Evaporation temperature” of a material is measured in a vacuum deposition tool at a constant pressure, normally between 1×10⁻⁷ Torr to 1×10⁻⁸ Torr, at a 2 Å/sec deposition rate on a surface positioned at a set distance away from the evaporation source of the material being evaporated, e.g. sublimation crucible in a VTE tool. The various measured values such as temperature, pressure, deposition rate, etc. disclosed herein are expected to have nominal variations because of the expected tolerances in the measurements that produced these quantitative values as understood by one of ordinary skill in the art.

Many factors other than temperature can contribute to the ability to achieve stable co-evaporation, such as the miscibility of the different materials and the phase transition temperatures of the different materials. The inventors found that when two materials have similar evaporation temperatures, and similar mass loss rate or similar vapor pressures, the two materials can co-evaporate consistently. “Mass loss rate” of a material is defined as the percentage of mass lost over time (“percentage/minute” or “%/min”) and is determined by measuring the time it takes to lose the first 10% of the mass of a sample of the material as measured by thermal gravity analysis (TGA) under a given experimental condition at a given constant temperature for a given material after the a steady evaporation state is reached. The given constant temperature is one temperature point that is chosen so that the value of mass loss rate is between about 0.05 to 0.50%/min. A skilled person in this field should appreciate that in order to compare two parameters, the experimental condition should be consistent. The method of measuring mass loss rate and vapor pressure is well known in the art and can be found, for example, in Bull. et al. Mater. Sci. 2011, 34, 7.

In the state of the art OLED devices, the EML may consist of three or more components. In one example, the EML can consist of two host-type compounds and an emitter combination (e.g. a hole transporting cohost (h-host), an electron transporting cohost (e-host), and a compound capable of functioning as an emitter in an OLED at room temperature). In another example, the EML can consist of one host-type compound and two emitter-type compounds (e.g., a host compound and two compounds each capable of functioning as an emitter in an OLED at room temperature). Conventionally, in order to fabricate such EMLs having three or more components using VTE process, three or more evaporation sources are required, one for each of the components. Because the concentration of the components are important for the device performance, typically, the rate of deposition of each component is measured individually during the deposition process. This makes the VTE process complicated and costly. Thus, it is desired to premix at least two of the components of such EMLs to reduce the number of VTE evaporation sources.

If any two of the three or more components of the EMLs can be premixed and form a stable mixture of co-evaporation source, then the number of evaporation sources required for EML layer fabrication would be reduced. In order for materials to be premixable into an evaporation source, they should co-evaporate and deposit uniformly without changing the ratio. The ratio of the components in the mixture should be the same as the ratio of the components in the evaporation deposited films from these premixed materials. Therefore, the concentration of the two components in the deposited film is controlled by their concentration in the premixed evaporation source.

This disclosure describes a new class of h- and e-hosts that can be premixed and stably co-evaporated from a single source.

According to one embodiment, a composition of materials comprising a first compound is disclosed. The first compound has a structure of formula:

In Formula I:

G¹ is selected from the group consisting of dibenzofuran, dibenzothiophene, dibenzoselenophene, and fluorene;

L¹, L² and L³ are each independently selected from the group consisting of direct bond, phenyl, biphenyl, terphenyl, pyridine, pyrimidine, and combinations thereof;

G⁴ is selected from the group consisting of phenyl, biphenyl, terphenyl, naphthalene, phenanthrene, pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, phenanthroline, and combinations thereof;

G², G³, and G⁵ are each independently selected from the group consisting of phenyl, biphenyl, terphenyl, fluorene, naphthalene, phenanthrene, pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, phenanthroline, aza-fluorene, and combinations thereof;

G², G³, G⁴, and G⁵ are each optionally further substituted with one or more unfused substituents selected from the group consisting of deuterium, alkyl, alkoxyl, cycloalkyl, cycloalkoxyl, halogen, nitro, nitrile, silyl, phenyl, biphenyl, terphenyl, pyridine, and combinations thereof;

m is an integer from 0 to 7,

n is an integer from 0 to 4;

when m or n is larger than 1, each G⁴ or G⁵ can be same or different;

when n is 0, m is equal to or greater than 1, and each G⁴ is selected from the group consisting of phenyl, and biphenyl;

when n is equal to or greater than 1, L¹ is not a direct bond; and

when m and n are both 0, L¹ is biphenyl.

In some embodiments, one or more of L¹, L² and L³ can be a direct bond, and the direct bond can be a single bond or a double bond. When L¹ is a direct bond, n=0.

In some embodiments, n is 0, while n is equal to or greater than 1 in other embodiments. In some embodiments, m and n are both 0. In some embodiments, m is equal to or greater than 1.

In some embodiments, G⁴ has the structure selected from the group consisting of:

In some embodiments, G¹ has the structure selected from the group consisting of:

wherein:

X is selected from a group consisting of O, S and Se;

R^(B1) and R^(B2) are independently selected from a group consisting of hydrogen, deuterium, alkyl, cycloalkyl, alkoxyl, aryl, heteraryl, halogen, and combinations thereof; and

R^(B1) and R^(B2) are optionally joined to form a ring.

In some embodiments, L¹ is selected from the group consisting of:

In some embodiments, G², G³ and G⁵ are independently selected from the group consisting of:

wherein

R^(B1) and R^(B2) are independently selected from a group consisting of hydrogen, deuterium, alkyl, cycloalkyl, alkoxyl, aryl, heteraryl, halogen, and combinations thereof; and

R^(B1) and R^(B2) are optionally joined to form a ring.

In some embodiments, at least one of G², G³, G⁴ and G⁵ is substituted with at least one fluorine atom.

In some embodiments, the first compound has the formula:

where X is selected from a group consisting of O, S and Se.

In some embodiments, the first compound is selected from the group consisting of:

In some embodiments, n is 0, m is 1, and G⁴-G¹ has a structure selected from the group consisting of:

In some embodiments, the first compound is selected from the group consisting of:

In some embodiments, the first compound has a formula:

where L¹ is biphenyl.

In some embodiments, the first compound is selected from the group consisting of:

In some embodiments, the composition comprises a second compound having a structure of formula II:

Formula II. In the structure of Formula II:

Ar¹ is selected from the group consisting of triphenylene, and aza-triphenylene;

Ar² is selected from the group consisting of a direct bond, phenyl, biphenyl, terphenyl, naphthalene, pyridine, dibenzofuran, dibenzothiophene, dibenzoselenophene, aza-dibenzofuran, aza-dibenzothiophene, aza-dibenzoselenophene, and combinations thereof;

Ar³ is selected from the group consisting of benzene, biphenyl, terphenyl, naphthalene, pyridine, dibenzofuran, dibenzothiophene, dibenzoselenophene, aza-dibenzofuran, aza-dibenzothiophene, aza-dibenzoselenophene, carbazole, aza-carbazole, and combinations thereof; and

Ar¹, Ar² and Ar³ are each, independently, optionally further substituted with one or more substitutions selected from the group consisting of deuterium, halogen, alkyl, aryl, heteroaryl, and combinations thereof.

In some embodiments, the second compound is selected from the group consisting of

where:

X is selected from the group consisting of O, S and Se;

R¹ and R⁴ each independently represents mono, di, or tri, substitution, or no substitution;

R², R³, R⁵, and R⁶ each independently represents mono, di, tri, or tetra substitution, or no substitution; and

R¹ to R⁶ are each independently selected from the group consisting of hydrogen, deuterium, benzene, biphenyl, terphenyl, naphthalene, fluorene, triphenylene, phenanthrene, dibenzofuran, dibenzothiophene, carbazole and combinations thereof.

In some embodiments, the second compound is selected from the group consisting of

In some embodiments, the mixture of the first compound and the second compound is selected from the group consisting of:

In some embodiments, the mixture of the first compound and the second compound is selected from the group consisting of:

In some embodiments, the composition comprises a second compound, where the second compound is a phosphorescent emissive Ir complex having at least one substituent selected from the group consisting of alkyl, cycloalkyl, partially or fully deuterated variants thereof; partially or fully fluorinated variants thereof; and combinations thereof.

According to another embodiment of the present disclosure, a composition of materials comprising a first compound having a structure of:

is disclosed. In the structure of Formula III,

L^(A) and L^(B) are selected from a group consisting of direct bond, phenyl, biphenyl, pyridine, and combinations thereof;

G^(A) and G^(B) are selected from a group consisting of phenyl, biphenyl, pyridine, dibenzothiophene, dibenzofuran, dibenzoselenophene, and fluorene; and

G^(A) and G^(B) are each optionally further substituted with one or more unfused substituents selected from the group consisting of deuterium, alkyl, alkoxyl, cycloalkyl, cycloalkoxyl, halogen, nitro, nitrile, silyl, phenyl, biphenyl, terphenyl, pyridine, and combinations thereof.

In some embodiments, one or more of L^(A) and L^(B) can be a direct bond, and the direct bond can be a single bond or a double bond.

In some embodiments, the first compound is selected from the group consisting of:

In some embodiments, the first compound has an evaporation temperature T1 of 150 to 350° C.; the second compound has an evaporation temperature T2 of 150 to 350° C.; an absolute value of T1-T2 is less than 20° C.; the first compound has a concentration C1 in said mixture and a concentration C2 in a film formed by evaporating the mixture in a vacuum deposition tool at a constant pressure between 1×10⁻⁶ Torr to 1×10⁻⁹ Torr, at a 2 Å/sec deposition rate on a surface positions at a predefined distance away from the mixture being evaporated; and the absolute value of (C₁-C₂)/C1 is less than 5%.

In some embodiments, the first compound has a vapor pressure of P1 at T1 at 1 atm, the second compound has a vapor pressure of P2 at T2 at 1 atm; and the ratio of P1/P2 is within the range of 0.90 to 1.10.

In some embodiments, the first compound has a first mass loss rate and the second compound has a second mass loss rate, wherein the ratio between the first mass loss rate and the second mass loss rate is within the range of 0.90 to 1.10.

In some embodiments, the first compound and the second compound each has a purity in excess of 99% as determined by high pressure liquid chromatography.

In some embodiments, the composition also comprises a third compound. In some embodiments, the third compound has a different chemical structure than the first and second compounds. In some embodiments, the third compound has a third mass loss rate and the ratio between the first mass loss rate and third mass loss rate is within the range of 0.90 to 1.10. In some embodiments, the third compound has an evaporation temperature T3 of 150 to 350° C., and the absolute value of T1-T3 is less than 20° C.

In some embodiments, the composition is in liquid form at a temperature less than T1 and T2.

In some embodiments, the composition comprises a second compound, where the second compound has the formula IV of

having the structure:

In such embodiments, Ar⁴ is selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl and combinations thereof; L¹¹ and L¹² are each independently selected from the group consisting of a direct bond, aryl, heteroaryl, alkyl, alkoxyl, and combinations thereof; p is an integer from 0 to 20; when p is greater than 1, each G⁷ can be same or different; R¹¹, R¹³, R¹⁵, and R¹⁶ each independently represents mono, di, tri, or tetra substitution, or no substitution; R¹² and R¹⁴ each independently represent mono, di, or tri substitution, or no substitution; R¹¹, R², R¹³, R¹⁴, R¹⁵, and R¹⁶ are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, silyl, carbonyl, alkyloxyl, nitrile, isonitrile, aryl, heteroaryl, and combinations thereof; and L¹¹, L¹², and Ar⁴ are each independently optionally further substituted by one or more substituents selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, silyl, carbonyl, alkyloxyl, nitrile, isonitrile, aryl, heteroaryl, and combinations thereof.

In some embodiments, the second compound is selected from the group consisting of:

In some embodiments, the second compound is selected from the group consisting of:

In some embodiments, the mixture of the first compound and the second compound is selected

from the group consisting of:

In some embodiments, the mixture of the first compound and the second compound is

In some embodiments, the first compound has an evaporation temperature T1 of 150 to 350° C., the second compound has an evaporation temperature T2 of 150 to 350° C., or both. In some embodiments, the absolute value of T1-T2 is less than 20° C. In some embodiments, the first compound has a concentration C1 in said mixture and a concentration C2 in a film formed by evaporating the mixture in a vacuum deposition tool at a constant pressure between 1×10⁻⁶ Torr to 1×10⁻⁹ Torr, at a 2 Å/sec deposition rate on a surface positione at a predefined distance away from the mixture being evaporated. In some embodiments, the absolute value of (C₁-C₂)/C1 is less than 5%.

In some embodiments, the first compound has a vapor pressure of P1 at T1 at 1 atm, the second compound has a vapor pressure of P2 at T2 at 1 atm; and the ratio of P1/P2 is within the range of 0.90 to 1.10.

In some embodiments, the first compound has a first mass loss rate and the second compound has a second mass loss rate, where the ratio between the first mass loss rate and the second mass loss rate is within the range of 0.90 to 1.10.

In some embodiments, the first compound and the second compound each has a purity in excess of 99% as determined by high pressure liquid chromatography.

In some embodiments, the composition further comprises a third compound, where the third compound has a different chemical structure than the first and second compounds. In some embodiments, the third compound has an evaporation temperature T3 of 150 to 350° C., and wherein absolute value of T1-T3 is less than 20° C. In some embodiments, the third compound has a third mass loss rate and the ratio between the first mass loss rate and third mass loss rate is within the range of 0.90 to 1.10.

In some embodiments, the composition is in liquid form at a temperature less than T1 and T2.

According to another aspect of the present disclosure, a device that includes one or more organic light emitting devices is also provided. At least one of the one or more organic light emitting devices can include an anode, a cathode, and an organic layer, disposed between the anode and the cathode. The organic layer can include a composition comprising a compound according to a structure of Formula I or Formula III, or any of the variations thereof described herein.

In some embodiments, the organic layer is an emissive layer and the composition comprises a host.

In some embodiments, the organic layer also includes a phosphorescent emissive dopant. In some embodiments, the phosphorescent emissive dopant is a transition metal complex having at least one ligand or part of the ligand if the ligand is more than bidentate selected from the group consisting of:

where:

each X¹ to X¹³ are independently selected from the group consisting of carbon and nitrogen;

X is selected from the group consisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO₂, CR′R″, SiR′R″, and GeR′R″;

R¹ and R″ are optionally fused or joined to form a ring;

each R_(a), R_(b), R_(c), and R_(d) may represent from mono substitution to the possible maximum number of substitution, or no substitution;

R′, R″, R_(a), R_(b), R_(c), and R_(d) are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

any two adjacent substitutents of R_(a), R_(b), R_(c), and R_(d) are optionally fused or joined to form a ring or form a multidentate ligand.

In some embodiments, the organic layer is a blocking layer and the composition is a blocking material in the organic layer. In some embodiments, the organic layer is an electron transporting layer and the composition is an electron transporting material in the organic layer.

In some embodiments, the first device is selected from the group consisting of a consumer product, an electronic component module, an organic light-emitting device, and a lighting panel.

In some embodiments, at least one of R_(a), R_(b), R_(c), and R_(d) is selected from the group consisting of alkyl, cycloalkyl, partially or fully deuterated variants thereof; partially or fully fluorinated variants thereof; and combinations thereof.

In yet another aspect of the present disclosure, a method for fabricating an organic light emitting device is provided. The organic light emitting device can include a first electrode, a second electrode, and a first organic layer disposed between the first electrode and the second electrode, where the first organic layer comprises a first composition comprising a mixture of a first compound and a second compound.

In some embodiments, the method includes providing a substrate having the first electrode disposed thereon; depositing the first composition over the first electrode; and depositing the second electrode over the first organic layer. In some embodiments, the first composition is selected from the group consisting of Formulation I and Formulation II, where Formulation I comprises a first compound of Formula I and a second compound of Formula II, and where Formulation II comprises a first compound of Formula III and a second compound of Formula IV.

Combination with Other Materials

The materials described herein as useful for a particular layer in an organic light emitting device may be used in combination with a wide variety of other materials present in the device. For example, emissive dopants disclosed herein may be used in conjunction with a wide variety of hosts, transport layers, blocking layers, injection layers, electrodes and other layers that may be present. The materials described or referred to below are non-limiting examples of materials that may be useful in combination with the compounds disclosed herein, and one of skill in the art can readily consult the literature to identify other materials that may be useful in combination.

HIL/HTL:

A hole injecting/transporting material to be used in the present invention is not particularly limited, and any compound may be used as long as the compound is typically used as a hole injecting/transporting material. Examples of the material include, but are not limited to: a phthalocyanine or porphyrin derivative; an aromatic amine derivative; an indolocarbazole derivative; a polymer containing fluorohydrocarbon; a polymer with conductivity dopants; a conducting polymer, such as PEDOT/PSS; a self-assembly monomer derived from compounds such as phosphonic acid and silane derivatives; a metal oxide derivative, such as MoO_(x); a p-type semiconducting organic compound, such as 1,4,5,8,9,12-Hexaazatriphenylenehexacarbonitrile; a metal complex, and a cross-linkable compound.

Examples of aromatic amine derivatives used in HIL or HTL include, but are not limited to the following general structures:

Each of Ar¹ to Ar⁹ is selected from the group consisting aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, azulene; group consisting aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine; and group consisting 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group. Wherein each Ar is further substituted by a substituent selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, Ar¹ to Ar⁹ is independently selected from the group consisting of:

wherein k is an integer from 1 to 20; X¹⁰¹ to X¹⁰⁸ is C (including CH) or N; Z¹⁰¹ is NAr¹, O, or S; Ar¹ has the same group defined above.

Examples of metal complexes used in HIL or HTL include, but are not limited to the following general formula:

wherein Met is a metal, which can have an atomic weight greater than 40; (Y¹⁰¹-Y¹⁰²) is a bidentate ligand, Y¹⁰¹ and Y¹⁰² are independently selected from C, N, O, P, and S; L¹⁰¹ is an ancillary ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal; and k′+k″ is the maximum number of ligands that may be attached to the metal.

In one aspect, (Y¹⁰¹-Y¹⁰²) is a 2-phenylpyridine derivative. In another aspect, (Y¹⁰¹-Y¹⁰²) is a carbene ligand. In another aspect, Met is selected from Ir, Pt, Os, and Zn. In a further aspect, the metal complex has a smallest oxidation potential in solution vs. Fc⁺/Fc couple less than about 0.6 V.

Host:

The light emitting layer of the organic EL device of the present invention preferably contains at least a metal complex as light emitting material, and may contain a host material using the metal complex as a dopant material. Examples of the host material are not particularly limited, and any metal complexes or organic compounds may be used as long as the triplet energy of the host is larger than that of the dopant. While the Table below categorizes host materials as preferred for devices that emit various colors, any host material may be used with any dopant so long as the triplet criteria is satisfied.

Examples of metal complexes used as host are preferred to have the following general formula:

wherein Met is a metal; (Y¹⁰³-Y¹⁰⁴) is a bidentate ligand, Y¹⁰³ and Y¹⁰⁴ are independently selected from C, N, O, P, and S; L¹⁰¹ is an another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal; and k′+k″ is the maximum number of ligands that may be attached to the metal.

In one aspect, the metal complexes are:

wherein (O—N) is a bidentate ligand, having metal coordinated to atoms O and N.

In another aspect, Met is selected from Ir and Pt. In a further aspect, (Y¹⁰³-Y¹⁰⁴) is a carbene ligand.

Examples of organic compounds used as host are selected from the group consisting aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, azulene; group consisting aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine; and group consisting 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group. Wherein each group is further substituted by a substituent selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, host compound contains at least one of the following groups in the molecule:

wherein R¹⁰¹ to R¹⁰⁷ is independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; when it is aryl or heteroaryl, it has the similar definition as Ar's mentioned above. k is an integer from 0 to 20 or 1 to 20; k″′ is an integer from 0 to 20. X¹⁰¹ to X¹⁰⁸ is selected from C (including CH) or N. Z¹⁰¹ and Z¹⁰² is selected from NR¹⁰¹, O, or S.

HBL:

A hole blocking layer (HBL) may be used to reduce the number of holes and/or excitons that leave the emissive layer. The presence of such a blocking layer in a device may result in substantially higher efficiencies as compared to a similar device lacking a blocking layer. Also, a blocking layer may be used to confine emission to a desired region of an OLED.

In one aspect, compound used in HBL contains the same molecule or the same functional groups used as host described above.

In another aspect, compound used in HBL contains at least one of the following groups in the molecule:

wherein k is an integer from 1 to 20; L¹⁰¹ is an another ligand, k′ is an integer from 1 to 3.

ETL:

Electron transport layer (ETL) may include a material capable of transporting electrons. Electron transport layer may be intrinsic (undoped), or doped. Doping may be used to enhance conductivity. Examples of the ETL material are not particularly limited, and any metal complexes or organic compounds may be used as long as they are typically used to transport electrons.

In one aspect, compound used in ETL contains at least one of the following groups in the molecule:

wherein R¹⁰¹ is selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; when it is aryl or heteroaryl, it has the similar definition as Ar's mentioned above. Ar¹ to Ar³ has the similar definition as Ar's mentioned above. k is an integer from 1 to 20. X¹⁰¹ to X¹⁰⁸ is selected from C (including CH) or N.

In another aspect, the metal complexes used in ETL include, but are not limited to the following general formula:

wherein (O—N) or (N—N) is a bidentate ligand, having metal coordinated to atoms O, N or N, N; L¹⁰¹ is another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal.

In any above-mentioned compounds used in each layer of the OLED device, the hydrogen atoms can be partially or fully deuterated. Thus, any specifically listed substituent, such as, without limitation, methyl, phenyl, pyridyl, etc. encompasses undeuterated, partially deuterated, and fully deuterated versions thereof. Similarly, classes of substituents such as, without limitation, alkyl, aryl, cycloalkyl, heteroaryl, etc. also encompass undeuterated, partially deuterated, and fully deuterated versions thereof.

In addition to and/or in combination with the materials disclosed herein, many hole injection materials, hole transporting materials, host materials, dopant materials, exciton/hole blocking layer materials, electron transporting and electron injecting materials may be used in an OLED. Non-limiting examples of the materials that may be used in an OLED in combination with materials disclosed herein are listed in Table A below. Table A lists non-limiting classes of materials, non-limiting examples of compounds for each class, and references that disclose the materials.

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EXPERIMENTAL Synthesis Examples

-   -   Chemical abbreviations used throughout this document are as         follows:     -   SPhos is         dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphine,     -   Pd₂(dba)₃ is tri(dibenzylideneacetone) dipalladium(0),     -   Pd(PPh₃)₄ is tetrakis(triphenylphosphine) palladium (0),     -   DCM is dichloromethane,     -   EtOAc is ethyl acetate,     -   DME is dimethyoxyethane, and     -   THF is tetrahydrofuran.

Synthesis of Compound A5 Synthesis of 4-(3-bromo-5-chlorophenyl)dibenzo[b,d]thiophene

Dibenzo[b,d]thiophen-4-ylboronic acid (3.0 g, 13.15 mmol) and 1,3-dibromo-5-chlorobenzene (10.67 g, 39.5 mmol) were dissolved in toluene (150 ml) under a nitrogen atmosphere in a nitrogen-flushed 250 mL two-necked round-bottomed flask to give a colorless solution. K₂CO₃ (7.27 g, 52.6 mmol) in water (50 ml) was added to the reaction mixture, followed by Pd(PPh₃)₄ (0.304 g, 0.263 mmol). The reaction mixture was then heated to reflux under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the organic phase was isolated, the solvent was evaporated, and the unreacted 1,3-dibromo-5-chlorobenzene was distilled off under reduced pressure. The residue was subjected to column chromatography on the silica gel with heptanes/DCM (9/1, v/v) as the eluent, to obtain 4-(3-bromo-5-chlorophenyl)dibenzo[b,d]thiophene (3.5 g, 71.2%) as a white solid.

Synthesis of 4-(5-chloro-[1,1′:4′,1″-terphenyl]-3-yl)dibenzo[b,d]thiophene

A solution of 4-(3-bromo-5-chlorophenyl)dibenzo[b,d]thiophene (4.0 g, 10.70 mmol), [1,1′-biphenyl]-4-ylboronic acid (2.120 g, 10.70 mmol), K₂CO₃ (3.0 g, 21.4 mmol) and Pd(PPh₃)₄ (0.37 g, 0.32 mmol) in toluene (150 ml) and water (50 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the organic layer was isolated and the solvent was evaporated. The residue was purified by column chromatography on silica gel with heptane/DCM (4/1, v/v) as the eluent to isolate 4-(5-chloro-[1,1′:4′,1″-terphenyl]-3-yl)dibenzo[b,d]thiophene (1.4 g 29%) as a white solid.

Synthesis of 2-(5-(dibenzo[b,d]thiophen-4-yl)-[1,1′:4′,1″-terphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

A mixture of 4-(5-chloro-[1,1′:4′,1″-terphenyl]-3-yl)dibenzo[b,d]thiophene (1.40 g, 3.13 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (1.59 g, 6.26 mmol), potassium acetate (0.92 g, 9.40 mmol), SPhos (0.25 g, 0.61 mmol) and Pd₂(dba)₃ (0.11 g, 0.12 mmol) in dioxane (150 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the reaction mixture was diluted with EtOAc, washed with brine and water, and dried over Na₂SO₄. Upon evaporation of the solvent, the residue was purified by column chromatography on silica gel with heptanes/EtOAc (9/1, v/v) as the eluent to yield 2-(5-(dibenzo[b,d]thiophen-4-yl)-[1,1′:4′,1″-terphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.1 g, 65%) as a white solid.

Synthesis of Compound A5

A solution of 2-chloro-4,6-diphenyl-1,3,5-triazine (1.84 g, 6.87 mmol), 2-(5-(dibenzo[b,d]thiophen-4-yl)-[1,1′:4′,1″-terphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.70 g, 6.87 mmol), Pd(PPh₃)₄ (0.16 g, 0.137 mmol), and K₂CO₃ (2.85 g, 20.61 mmol) in DME (150 ml), toluene (100 ml) and water (50 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the solid was isolated by filtration, and washed successively with water, methanol, and EtOAc. The crude product was dissolved in hot toluene, filtered through a short plug of silica gel and recrystallized from toluene to yield Compound A5 (3.1 g, 70%) as a white solid.

Synthesis of Compound A11 Synthesis of 4-(5-chloro-[1,1′-biphenyl]-3-yl)-6-phenyldibenzo[b,d]thiophene

A solution of 3-bromo-5-chloro-1,1′-biphenyl (10 g, 37.4 mmol), (6-phenyldibenzo[b,d]thiophen-4-yl)boronic acid (11.37 g, 37.4 mmol), Pd(PPh₃)₄ (0.432 g, 0.374 mmol), and K₂CO₃ (10.33 g, 74.8 mmol) in toluene (150 ml) and water (30 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the organic phase was isolated and the solvent was evaporated. The residue was purified by column chromatography on silica gel with heptane/DCM (4/1, v/v) as the eluent to yield 4-(5-chloro-[1,1′-biphenyl]-3-yl)-6-phenyldibenzo[b,d]thiophene (12.1 g, 72.4%) as a white solid.

Synthesis of 4,4,5,5-tetramethyl-2-(5-(6-phenyldibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-1,3,2-dioxaborolane

A solution of 4-(5-chloro-[1,1′-biphenyl]-3-yl)-6-phenyldibenzo[b,d]thiophene (13.0 g, 29.1 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (14.77 g, 58.2 mmol), Pd₂(dba)₃ (0.20 g, 0.22 mmol), SPhos (0.35 g, 0.85 mmol), and potassium acetate (8.56 g, 87 mmol) in dioxane (200 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the reaction solution was quenched with water and extracted with EtOAc. The combined organic extracts were dried over Na₂SO₄ and the solvent was evaporated. The residue was purified by column chromatography on silica gel with heptane/EtOAc (9/1, v/v) as the eluent to yield 4,4,5,5-tetramethyl-2-(5-(6-phenyldibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-1,3,2-dioxaborolane (13.2 g, 84%) as a white solid.

Synthesis of Compound A11

A solution of 4,4,5,5-tetramethyl-2-(5-(6-phenyldibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-1,3,2-dioxaborolane (3.55 g, 6.59 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (1.765 g, 6.59 mmol), Pd(PPh₃)₄ (0.152 g, 0.132 mmol), and K₂CO₃ (1.822 g, 13.18 mmol) in toluene (100 ml), DME (100 ml) and water (50 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the organic layer was isolated, filtered through a short plug of silica gel and concentrated. The precipitate was collected, washed successively with heptane, ethanol, and heptane to yield Compound A11 (3.9 g, 92%) as a white solid.

Synthesis of Compound A14

A solution of 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.44 g, 7.44 mmol), 2-(5-chloro-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine (2.92 g, 6.95 mmol), Pd₂(dba)₃ (0.159 g, 0.174 mmol), SPhos (0.4 g, 0.976 mmol), and K₃PO₄ (4.80 g, 20.9 mmol) in toluene (125 ml), DME (100 ml) and water (25 ml) was refluxed under nitrogen for 18 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, dissolved in boiling toluene (800 ml), and filtered through a short plug of silica gel. Upon evaporation off the solvent, Compound A14 (3.50 g, 70%) was recrystallized from toluene to yield a white solid.

Synthesis of Compound A17

A solution of 2-(6-([1,1′-biphenyl]-3-yl)dibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.51 g, 7.60 mmol), 2-(5-chloro-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine (2.9 g, 6.91 mmol), Pd₂(dba)₃ (0.190 g, 0.207 mmol), SPhos (0.5 g, 1.220 mmol), and K₃PO₄ (4.77 g, 20.7 mmol) in toluene (125 ml), DME (100 ml) and water (20 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, dissolved in boiling toluene (800 ml) and filtered through a short plug of silica gel. Upon evaporation off the solvent, Compound A17 (3.75 g, 76%) was recrystallized from toluene to yield a white solid.

Synthesis of Compound A32 Synthesis of 4-(5-chloro-[1,1′-biphenyl]-3-yl)dibenzo[b,d]thiophene

A solution of 3-bromo-5-chloro-1,1′-biphenyl (14.8 g, 55.3 mmol), dibenzo[b,d]thiophen-4-ylboronic acid (12.62 g, 55.3 mmol), Pd(PPh₃)₄ (0.639 g, 0.553 mmol) and K₂CO₃ (15.29 g, 111 mmol) in toluene (150 ml) and water (30 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the organic phase was isolated. After evaporating off the solvent, the residue was purified by column chromatography on silica gel with heptane/DCM (85/15,v/v) as the eluent to yield 4-(5-chloro-[1,1′-biphenyl]-3-yl)dibenzo[b,d]thiophene (15.4 g, 70%) as a white solid.

Synthesis of 2-(5-(dibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

A solution of 4-(5-Chloro-[1,1′-biphenyl]-3-yl)dibenzo[b,d]thiophene (11.88 g, 32.0 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (16.27 g, 64.1 mmol), Pd₂(dba)₃ (280 mg), SPhos (0.32 g, 0.78 mmol), and potassium acetate (9.43 g, 96 mmol) in dioxane (200 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the reaction mixture was quenched with water and extracted with EtOAc. After evaporating off the solvent, the residue was purified by column chromatography on silica gel with heptane/EtOAc (9/1, v/v) as the eluent and recrystallization from heptane to yield 2-(5-(dibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (11.1 g, 74.9%) as a white solid.

Synthesis of Compound A32

A solution of 2-([1,1′-biphenyl]-4-yl)-4-chloro-6-phenyl-1,3,5-triazine (2.24 g, 6.52 mmol), 2-(5-(dibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.01 g, 6.52 mmol), Pd(PPh₃)₄ (0.151 g, 0.130 mmol) and K₂CO₃ (1.801 g, 13.03 mmol) in toluene (180 ml), DME (30 ml), and water (30 ml) was refluxed under nitrogen for 12 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration and washed successively with ethanol, water, and ethanol. The crude product was recrystallized from toluene to yield Compound A32 (2.7 g, 64%) as a white solid.

Synthesis of Compound A35

A solution of 2,4-di([1,1′-biphenyl]-4-yl)-6-chloro-1,3,5-triazine (3.0 g, 7.14 mmol) and 2-(5-(dibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.30 g, 7.14 mmol), Pd(PPh₃)₄ (0.164 g, 0.14 mmol), and K₂CO₃ (1.975 g, 14.29 mmol) in toluene (100 ml), DME (100 ml), and water (50 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (22° C.), the solid was collected by filtration and washed successively with ethanol, water, ethanol, and heptane. The crude product was dissolved in hot toluene, filtered through a short plug of silica gel and recrystallized from toluene to yield Compound A35 (3.7 g, 72% yield) as a white solid.

Synthesis of Compound A38 Synthesis of 2-chloro-4-(9,9-dimethyl-9H-fluoren-2-yl)-6-phenyl-1,3,5-triazine

A Grignard reagent solution prepared by refluxing 2-bromo-9,9-dimethyl-9H-fluorene (19.33 g, 70.8 mmol) and Mg (2.58 g, 106 mmol) in dry THF (100 ml) under nitrogen for 2 h was transferred dropwise into a solution of 2,4-dichloro-6-phenyl-1,3,5-triazine (8.0 g, 35.4 mmol) in dry THF (50 ml) at room temperature (˜22° C.). The reaction mixture was stirred under nitrogen overnight (˜12 hours), quenched with concentrated HCl solution and extracted with EtOAc. The organic phase was isolated and the solvent was evaporated. The residue was purified by column chromatography on silica gel with heptane/DCM (9/1, v/v) as the eluent and recrystallization from heptane to yield 2-chloro-4-(9,9-dimethyl-9H-fluoren-2-yl)-6-phenyl-1,3,5-triazine (11 g, 81%) as yellow crystals.

Synthesis of Compound A38

A solution of 2-chloro-4-(9,9-dimethyl-9H-fluoren-2-yl)-6-phenyl-1,3,5-triazine (3.0 g, 7.82 mmol), 2-(5-(dibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.61 g, 7.82 mmol), Pd(PPh₃)₄ (0.18 g, 0.156 mmol) and K₂CO₃ (2.16 g, 15.63 mmol) in toluene (100 ml), DME (100 ml) and water (50 ml) was refluxed under nitrogen for 12 h. After cooling to room temperature (˜22° C.), the organic phase was isolated and the solvent was evaporated. The residue was purified by column chromatography on silica gel with heptane/DCM (6/4, v/v) as the eluent and trituration with heptane to yield Compound A38 (4.3 g, 80%) as a white solid.

Synthesis of Compound A41

A solution of 4,4,5,5-tetramethyl-2-(5-(6-phenyldibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-1,3,2-dioxaborolane (1.98 g, 3.68 mmol), 2-([1,1′-biphenyl]-3-yl)-4-chloro-6-phenyl-1,3,5-triazine (1.264 g, 3.68 mmol), Pd(PPh₃)₄ (0.085 g, 0.074 mmol), and K₂CO₃ (1.016 g, 7.35 mmol) in DME (150 ml) and water (5 ml) was refluxed under nitrogen for 12 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, washed successively with ethanol, water, ethanol, and heptane, then dissolved in boiling toluene and filtered through a short plug of silica gel. Upon evaporation off the solvent, Compound A41 (2.3 g, 87%) was recrystallized from toluene to yield a white solid.

Synthesis of Compound A47

A solution of 4,4,5,5-tetramethyl-2-(5-(6-phenyldibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-1,3,2-dioxaborolane (3.18 g, 5.91 mmol), 2-chloro-4-(9,9-dimethyl-9H-fluoren-2-yl)-6-phenyl-1,3,5-triazine (2.267 g, 5.91 mmol) Pd(PPh₃)₄ (0.136 g, 0.118 mmol) and potassium carbonate (1.632 g, 11.81 mmol) in toluene (30 ml), DME (100 ml) and water (20 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the organic layer was isolated and the solvent was evaporated. The residue was purified by column chromatography on silica gel with heptane/DCM (1/1, v/v) as the eluent to yield Compound A47 (2.1 g, 47%) as a white solid.

Synthesis of Compound A110

A solution of 2-(5-(dibenzo[b,d]thiophen-4-yl)-[1,1′-biphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.70 g, 3.68 mmol), 2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine (1.43 g, 3.68 mmol), Pd(PPh₃)₄ (0.085 g, 0.074 mmol), and K₂CO₃ (1.02 g, 7.35 mmol) in DME (120 ml) and water (20 ml) was refluxed under nitrogen for 14 h. After cooling to room temperature (˜22° C.), the precipitate was collected by filtration, washed successively with ethanol, water, ethanol and heptane to yield Compound A110 (2.1 g, 89% yield). as a white solid.

Synthesis of Compound A113

A solution of 2-(5-chloro-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine (3.4 g, 8.10 mmol), 2-(4-(dibenzo[b,d]thiophen-4-yl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.28 g, 8.50 mmol), Pd₂(dba)₃ (0.222 g, 0.243 mmol), SPhos (0.199 g, 0.486 mmol), and K₂CO₃ (3.36 g, 24.29 mmol) in toluene (16 ml), DME (48 ml), and water (16 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration and triturated with ethanol. The crude product was dissolved in boiling toluene, then filtered through a short plug of silica gel, and recrystallized from toluene to yield Compound A113 (4.25 g, 82%) as a white solid.

Synthesis of Compound A116 Synthesis of 2-(3-bromo-5-chlorophenyl)-9,9-dimethyl-9H-fluorene

A solution of (9,9-Dimethyl-9H-fluoren-2-yl)boronic acid (5.0 g, 21.0 mmol), 1,3-dibromo-5-chlorobenzene (14.19 g, 52.5 mmol), Pd(PPh₃)₄ (0.49 g, 0.42 mmol), and K₂CO₃ (5.80 g, 42.0 mmol) in toluene (200 ml) and water (50 ml) was refluxed under nitrogen for 18 h. After cooling to room temperature (˜22° C.), the organic layer was isolated and the excess of 1,3-dibromo-5-chlorobenzene was distilled off. The residue was purified by column chromatography on silica gel with heptane/DCM (9/1, v/v) as the eluent to yield 2-(3-bromo-5-chlorophenyl)-9,9-dimethyl-9H-fluorene (6.2 g, 77%) as a colorless crystalline solid.

Synthesis of 4-(3-chloro-5-(9,9-dimethyl-9H-fluoren-2-yl)phenyl)dibenzo[b,d]thiophene

A solution of 2-(3-bromo-5-chlorophenyl)-9,9-dimethyl-9H-fluorene (7.7 g, 20.07 mmol), dibenzo[b,d]thiophen-4-ylboronic acid (4.58 g, 20.07 mmol), Pd(PPh₃)₄ (0.464 g, 0.401 mmol), and K₂CO₃ (5.55 g, 40.1 mmol) in DME (150 ml) and water (20 ml) was refluxed under nitrogen for 12 h. After cooling to room temperature (˜22° C.), the organic phase was isolated and the solvent was evaporated. The crude product was purified by column chromatography on silica gel with heptane/DCM (9/1 to 4/1, v/v) as the eluent to yield 4-(3-chloro-5-(9,9-dimethyl-9H-fluoren-2-yl)phenyl)dibenzo[b,d]thiophene (9.0 g, 92%) as a white crystalline solid.

Synthesis of 2-(3-(dibenzo[b,d]thiophen-4-yl)-5-(9,9-dimethyl-9H-fluoren-2-yl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

A solution of 4-(3-chloro-5-(9,9-dimethyl-9H-fluoren-2-yl)phenyl)dibenzo[b,d]thiophene (9.5 g, 19.51 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (9.91 g, 39.0 mmol), Pd₂(dba)₃ (0.268 g, 0.293 mmol), SPhos (0.240 g, 0.585 mmol), and potassium acetate (5.74 g, 58.5 mmol) in dioxane was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the reaction mixture was diluted with water and extracted with ethyl acetate. The combined organic extracts were filtered and evaporated. The crude product was purified by column chromatography on silica gel with heptane/DCM (1/1, v/v) as the eluent to yield 2-(3-(dibenzo[b,d]thiophen-4-yl)-5-(9,9-dimethyl-9H-fluoren-2-yl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (7.8 g, 69.1%) as a white crystalline solid.

Synthesis of Compound A116

A solution of 2-(3-(dibenzo[b,d]thiophen-4-yl)-5-(9,9-dimethyl-9H-fluoren-2-yl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (5.84 g, 10.09 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (2.70 g, 10.09 mmol), Pd(PPh₃)₄ (0.233 g, 0.202 mmol), and K₂CO₃ (3.49 g, 25.2 mmol) in DME (100 ml), toluene (100 ml), and water (50 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the precipitate was collected by filtration, then washed successively with water, ethanol, and heptane to yield Compound A116 (5.5 g, 80%) as a white solid.

Synthesis of Compound B3

A solution of 2-(5-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′: 4′,1″-terphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3 g, 5.47 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (1.464 g, 5.47 mmol), Pd(PPh₃)₄ (0.126 g, 0.109 mmol), and K₂CO₃ (1.512 g, 10.94 mmol) in toluene (75 ml), DME (75 ml), and water (20 ml) was refluxed under nitrogen for 6 h. After cooling to room temperature (˜22° C.), the precipitate was collected by filtration, then washed successively with water, ethanol, heptanes, and ethanol to yield Compound B3 (2.8 g, 78%) as a white solid.

Synthesis of Compound B6 Synthesis of 2-(5-chloro-[1.1′: 4′,1″-terphenyl]-3-yl)-9,9-dimethyl-9H-fluorene

A solution of 2-(3-bromo-5-chlorophenyl)-9,9-dimethyl-9H-fluorene (5 g, 13.03 mmol), [1,1′-biphenyl]-4-ylboronic acid (2.58 g, 13.03 mmol), Pd(PPh₃)₄ (0.301 g, 0.261 mmol), and K₂CO₃ (5.40 g, 39.1 mmol) in DME (150 ml) and water (25 ml) was refluxed under nitrogen for 12 h. After cooling to room temperature (˜22° C.), the organic phase was isolated and the solvent was evaporated. The crude product was purified by column chromatography on silica gel with heptane/DCM (1/1, v/v) as the eluent and recrystallized from heptane to yield 2-(5-chloro-[1,1′:4′,1″-terphenyl]-3-yl)-9,9-dimethyl-9H-fluorene (3.6 g, 60.5%) as colorless crystals.

Synthesis of 2-(5-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′:4′,1″-terphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

A solution of 2-(5-chloro-[1,1′:4′,1″-terphenyl]-3-yl)-9,9-dimethyl-9H-fluorene (6.8 g, 14.88 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (7.56 g, 29.8 mmol), Pd₂(dba)₃ (0.273 g, 0.298 mmol), SPhos (0.244 g, 0.595 mmol), and potassium acetate (2.92 g, 29.8 mmol) in dioxane (100 ml) and DME (100 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the solid was filtered off. Upon evaporating off the solvent, the residue was purified by column chromatography on silica gel with heptane/DCM (1/1,v/v) as the eluent to yield 2-(5-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′:4′,1″-terphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (5.0 g, 61.3%) as a white solid.

Synthesis of Compound B6

A solution of 2-(5-(9,9-Dimethyl-9H-fluoren-2-yl)-[1,1′:4′,1″-terphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (5.17 g, 9.43 mmol), 2-chloro-4-(9,9-dimethyl-9H-fluoren-2-yl)-6-phenyl-1,3,5-triazine (3.62 g, 9.43 mmol), Pd(PPh₃)₄ (0.218 g, 0.189 mmol), and potassium carbonate (2.61 g, 18.85 mmol) in DME (75 ml), toluene (75 ml), and water (10 ml) was refluxed under nitrogen for 15 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, then washed successively with ethanol, water, ethanol, and heptane to yield Compound B6 (4.2 g, 58%) as a white crystalline solid.

Synthesis of Compound B7

A solution of 2-(3,5-bis(9,9-dimethyl-9H-fluoren-2-yl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4 g, 6.80 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (1.819 g, 6.80 mmol), Pd(PPh₃)₄ (0.079 g, 0.068 mmol), and K₂CO₃ (1.878 g, 13.59 mmol) in DME (75 ml), toluene (75 ml), and water (10 ml) was refluxed under nitrogen for 18 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, then washed successively with ethanol, water, ethanol and heptane to yield Compound B7 (3.5 g, 74%) as a white crystalline solid.

Synthesis of Compound C21 Synthesis of 2-(dibenzo[b,d]selenophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Into a solution of dibenzo[b,d]selenophene (7 g, 30.3 mmol) in anhydrous THF (151 ml) a solution of sec-butyllithium (23.79 ml, 33.3 mmol) was added dropwise at −78° C. The resulting mixture was stirred at this temperature for 2 h and warmed to room temperature (˜22° C.). After cooling the mixture to −78° C., the mixture was quenched with 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (7.72 ml, 37.9 mmol) by syringe over ˜1 minute, then gradually warmed to room temperature (22° C.) and stirred overnight (˜12 hours). The resulting mixture was quenched with methanol and the solvent was removed in vacuo. The crude product was purified by column chromatography on silica gel with heptane/DCM (4/1 to 1/1, v/v) as the eluent to yield 2-(dibenzo[b,d]selenophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (7 g, 65%) as a yellow oil.

Synthesis of 4-phenyldibenzo[b,d]selenophene

A solution of 2-(dibenzo[b,d]selenophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (7.0 g, 19.60 mmol), iodobenzene (2.62 ml, 23.52 mmol), Pd(PPh₃)₄ (0.453 g, 0.392 mmol), and K₂CO₃ (8.13 g, 58.8 mmol) in THF (78 ml) and water (19.60 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (22° C.), the reaction mixture was partitioned with ethyl acetate and water. The organic phase was isolated, then washed with brine and dried over Na₂SO₄. After evaporating the solvent, the residue was purified by column chromatography on silica gel with heptane/DCM (9/1, v/v) as the eluent to yield 4-phenyldibenzo[b,d]selenophene (5.3 g, 88%) as a colorless oil.

Synthesis of 4,4,5,5-tetramethyl-2-(6-phenyldibenzo[b,d]selenophen-4-yl)-1,3,2-dioxaborolane

A solution of 4-phenyldibenzo[b,d]selenophene (5.3 g, 17.25 mmol) in THF (108 ml) was cooled to −78° C. and treated slowly with a solution of sec-butyllithium 1.4 M (16.63 ml, 23.29 mmol) in cyclohexane. The resulting mixture was stirred at this −78° C. for 1 h before being allowed to warm to room temperature (˜22° C.). The dark red solution was cooled to −78° C. and quenched with 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (5.28 ml, 25.9 mmol) by syringe. The reaction mixture was allowed to warm gradually to room temperature (˜22° C.) and stirred for 16 h. The resulting mixture was quenched with methanol, then the solvent was removed in vacuo. The residue was dissolved in DCM, washed with water and brine, and then dried over Na₂SO₄. After evaporating the solvent, the crude product was recrystallized from heptane to yield 4,4,5,5-tetramethyl-2-(6-phenyldibenzo[b,d]selenophen-4-yl)-1,3,2-dioxaborolane (5 g, 67%) as a pale yellow solid.

Synthesis of Compound C21

A solution of 4,4,5,5-tetramethyl-2-(6-phenyldibenzo[b,d]selenophen-4-yl)-1,3,2-dioxaborolane (2.0 g, 4.62 mmol), 2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine (1.882 g, 4.85 mmol), Pd(PPh₃)₄ (0.160 g, 0.139 mmol), and K₂CO₃ (1.914 g, 13.85 mmol) in DME (28 ml), toluene (9 ml), and water (9 ml) was refluxed under nitrogen for 8 h. After cooling to room temperature (22° C.), the solids were collected by filtration, then washed with water and ethanol, dissolved in boiling toluene, and finally filtered through a short plug of silica gel. After evaporating the solvent, Compound C21 (2.6 g, 74%) recrystallized from toluene as a white solid.

Synthesis of Compound C23

A solution of 4,4,5,5-tetramethyl-2-(3-(6-phenyldibenzo[b,d]thiophen-4-yl)phenyl)-1,3,2-dioxaborolane (3.0 g, 6.49 mmol), 2-([1,1′-biphenyl]-4-yl)-4-chloro-6-phenyl-1,3,5-triazine (2.454 g, 7.14 mmol), Pd(PPh₃)₄ (0.375 g, 0.324 mmol), and K₂CO₃ (2.69 g, 19.46 mmol) in toluene (13 ml), DME (39 ml), and water (13 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the solids were collected by filtration, then triturated with ethanol, dissolved in boiling toluene, and filtered through a short plug of silica gel. After evaporating the solvent, Compound C23 (3.78 g, 91%) recrystallized from toulene as a white solid.

Synthesis of Compound C29

A solution of 2-(4-chlorophenyl)-4,6-diphenyl-1,3,5-triazine (2.75 g, 8.00 mmol), 6-phenyl-dibenzo[b,d]thiophen-4-yl boronic acid (2.68 g, 8.80 mmol), Pd₂(dba)₃ (0.20 g, 0.22 mmol) and SPhos (0.40 g, 0.98 mmol), and K₃PO₄ (5.52 g, 24.00 mmol) in toluene (150 ml), DME (125 ml) and water (30 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the precipitate was collected by filtration and washed with water and DCM, before being dissolved in boiling toluene and filtered through a short plug of silica gel. After evaporating the solvent, Compound C29 (2.42 g, 53%) was recrystallized from toluene to give a white solid.

Synthesis of Compound C47

A suspension of 4,4,5,5-tetramethyl-2-(3-(6-phenyldibenzo[b,d]thiophen-4-yl)phenyl)-1,3,2-dioxaborolane (3.09 g, 6.69 mmol), 2-(4-chlorophenyl)-4,6-diphenyl-1,3,5-triazine (2.3 g, 6.69 mmol), Pd₂(dba)₃ (0.123 g, 0.134 mmol), and SPhos (0.110 g, 0.268 mmol) and K₃PO₄ (4.26 g, 20.07 mmol) in toluene (20 ml), DME (30 ml), and water (10 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, then dissolved in boiling toluene, filtered through a short plug of silica, and recrystallized from toluene to yield Compound C47 (3.51 g, 81%) as a white solid.

Synthesis of Compound C56

A solution of 4,4,5,5-tetramethyl-2-(4-(6-phenyldibenzo[b,d]thiophen-4-yl)phenyl)-1,3,2-dioxaborolane (3.5 g, 7.57 mmol), 2-(3-chlorophenyl)-4,6-diphenyl-1,3,5-triazine (2.169 g, 6.31 mmol), Pd₂(dba)₃ (0.17 g, 0.19 mmol), SPhos (0.23 g, 0.57 mmol), and K₃PO₄ (4.02 g, 18.9 mmol) in toluene (100 ml), DME (100 ml), and water (10 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the reaction mixture was filtered through a plug of silica gel. After evaporating the solvent, the residue was purified by column chromatography on silica gel with heptane/DCM (9/1 to 4/1,v/v) as eluent and recrystallization from DCM to yield Compound C56 (2.2 g, 54%) as a white solid.

Synthesis of Compound C65

A mixture solution of 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.75 g, 8.11 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (2.61 g, 9.73 mmol), Pd₂(dba)₃ (0.149 g, 0.162 mmol), SPhos (0.266 g, 0.649 mmol), and potassium phosphate hydrate (3.74 g, 16.22 mmol) in toluene (90 mL) and water (10 mL) was refluxed under nitrogen overnight (˜12 hours). Upon completion, the toluene was evaporated and the mixture was extracted with dichloromethane (not completely soluble) and washed with brine and water. The organic layers were combined, dried over Na₂SO₄, and concentrated under vacuum. The crude materials was triturated with ethanol and then with toluene to yield Compound C65 (3.0 g, 65%) as a light-yellow solid.

Synthesis of Compound C68

A solution of 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4 g, 8.65 mmol), 2-([1,1′-biphenyl]-4-yl)-4-chloro-6-phenyl-1,3,5-triazine (2.75 g, 8.00 mmol), Pd(PPh₃)₄ (0.28 g, 0.24 mmol), and K₂CO₃ (3.31 g, 24 mmol) in toluene (125 ml), DME (100 ml) and water (25 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the precipitate was collected by filtration then rinsed with toulene. The crude product was triturated successively with toluene and methanol, then sublimed under vacuum to yield Compound C68 (4.25 g, 83%) as a white solid.

Synthesis of Compound C71

A suspension of 2-([1,1′-biphenyl]-3-yl)-4-chloro-6-phenyl-1,3,5-triazine (2.1 g, 6.11 mmol), 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.82 g, 6.11 mmol), Pd(PPh₃)₄ (0.141 g, 0.122 mmol), and K₂CO₃ (2.53 g, 18.32 mmol) in DME (150 ml) and water (20 ml) was refluxed under nitrogen for 3 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, then washed with water and ethanol. The solid was dissolved in boiling toluene, filtered through a short plug of silica gel. After evaporating the solvent, the crude product was recrystallized from toluene to yield Compound C71 (2.9 g, 74%) as a light-yellow solid.

Synthesis of Compound C73

A solution of 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]furan-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.2 g, 9.41 mmol), 2-(3-chlorophenyl)-4,6-diphenyl-1,3,5-triazine (3.46 g, 10.07 mmol), Pd₂(dba)₃ (0.258 g, 0.282 mmol), SPhos (0.463 g, 1.129 mmol), and K₃PO₄ (6.49 g, 28.2 mmol) in toluene (125 ml), DME (100 ml), and water (25 ml) was refluxed under nitrogen for 18 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, dissolved in boiling toluene, filtered through a short plug of silica gel, and recrystallized from toluene to yield Compound C73 (4.5 g, 76%) as a white solid.

Synthesis of Compound C74

A solution of 2,4-diphenyl-6-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,3,5-triazine (2.64 g, 6.07 mmol), 4-([1,1′-biphenyl]-4-yl)-6-bromodibenzo[b,d]thiophene (2.53 g, 6.10 mmol), Pd₂(dba)₃ (0.139 g, 0.152 mmol), SPhos (0.187 g, 0.455 mmol), and K₃PO₄ (2.146 g, 10.11 mmol) in toluene (75 ml), DME (75 ml), and water (7.50 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the solid was collected by filtration, purified by column chromatography on silica gel with heptane/DCM (4/1 to 7/3, v/v) as eluent and recrystallization from heptane to yield Compound C74 (2.0 g, 61%) as a white solid.

Synthesis of Compound C75 Synthesis of 4-([1,1′-biphenyl]-4-yl)dibenzo[b,d]selenophene

A solution of 4-iodo-dibenzo[b,d]selenophene (10 g, 28.0 mmol), [1,1′-biphenyl]-4-ylboronic acid (8.32 g, 42.0 mmol), Pd(PPh₃)₄ (1.624 g, 1.400 mmol), and K₂CO₃ (7.74 g, 56.0 mmol) in DME (200 ml) and water (40 ml) was refluxed under nitrogen for 24 h. After cooling to room temperature (22° C.), the solid was collected by filtration, washed with water and heptane, then dissolved in boiling toluene and filtered through a short plug of silica gel. After evaporating the solvent, 4-([1,1′-biphenyl]-4-yl)dibenzo[b,d]selenophene (8.0 g, 74%) was recrystallized from toluene as a white solid.

Synthesis of 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]selenophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Into a solution of 4-([1,1′-biphenyl]-4-yl)dibenzo[b,d]selenophene (5.5 g, 14.35 mmol) in THF (150 ml) a solution of sec-butyl lithium (18.45 ml, 25.8 mmol) was added dropwise at −78° C. The resulting mixture was stirred at −78° C. for 5 h before 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (5.12 ml, 25.1 mmol) was added in one portion. The reaction mixture was gradually warmed to room temperature (˜22° C.) and stirred for 16 h before quenching with water. The resulting mixture was extracted with ethyl acetate, then dried over Na₂SO₄. After evaporating the solvent, the residue was purified by column chromatography on silica gel with heptane/DCM (4/1 to 3/2, v/v) as the eluent to yield 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]selenophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.6 g, 36%) as a white solid.

Synthesis of Compound C75

A solution of 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]selenophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.62 g, 5.15 mmol), 2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine (2 g, 5.15 mmol), Pd(PPh₃)₄ (0.179 g, 0.155 mmol), and K₂CO₃ (1.424 g, 10.30 mmol) in DME (150 ml), toluene (50 ml), and water (40 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, washed successively with water and heptane, then dissolved in boiling toluene and filtered through a short plug of silica gel. The crude product further purified by recrystallized successively from heptane and toluene to yield Compound C75 (2.1 g, 59%) as white crystals.

Synthesis of Compound C83

A suspension of 2-(4-chlorophenyl)-4,6-diphenyl-1,3,5-triazine (2.409 g, 7.01 mmol), 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.7 g, 5.84 mmol), Pd₂(dba)₃ (0.107 g, 0.117 mmol), SPhos (0.096 g, 0.234 mmol), and K₂CO₃ (2.421 g, 17.52 mmol) in toluene (20 ml), DME (65 ml), and water (15 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the reaction mixture was diluted with water. The solid was collected by filtration, washed with water and ethanol, redissolved in hot toluene, and filtered through a short plug of silica gel. After evaporating the solvent, the residue was recrystallized from EtOAc to yield Compound C83 (3.2 g, 85%) as a white solid.

Synthesis of Compound C101

A solution of 2-(6-([1,1′-biphenyl]-3-yl)dibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.03 g, 8.73 mmol), 2-(3-chlorophenyl)-4,6-diphenyl-1,3,5-triazine (2.50 g, 7.27 mmol), Pd₂(dba)₃ (0.20 g, 0.22 mmol), SPhos (0.27 g, 0.65 mmol), and K₃PO₄ (4.63 g, 21.8 mmol) in toluene (100 ml), DME (100 ml), and water (10 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (22° C.), the reaction mixture was diluted with DCM and filtered through a plug of silica gel. After evaporating the solvent, the residue was purified by column chromatography on silica gel with heptane/DCM (4/1 to 3/2, v/v) as the eluent and recrystallization from DCM to yield Compound C101 (1.6 g, 43%) as a white solid.

Synthesis of Compound C110

A suspension of 2-(6-([1,1′-biphenyl]-3-yl)dibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.1 g, 6.70 mmol), 2-(4-chlorophenyl)-4,6-diphenyl-1,3,5-triazine (2.54 g, 7.37 mmol), Pd₂(dba)3 (0.123 g, 0.134 mmol), and SPhos (0.110 g, 0.268 mmol), and K₃PO₄ (4.27 g, 20.11 mmol) in toluene (20.00 ml), DME (30.0 ml) and water (10 ml) was refluxed under nitrogen overnight. After cooling to room temperature, it was diluted with water and the soild was collected by filtration and washed with ethanol. The crude product was dissolved in boilng toluene and filtered through a short plug of silica gel. Upon evaporation off the solvent, Compound C110 (4.2 g, 97%) was recrystallized from toluene as a white solid.

Synthesis of Compound C119

A solution of (6-phenyldibenzo[b,d]thiophen-4-yl)boronic acid (3.14 g, 10.32 mmol), 2-chloro-4-(9,9-dimethyl-9H-fluoren-2-yl)-6-phenyl-1,3,5-triazine (3.6 g, 9.38 mmol), Pd(PPh₃)₄ (0.217 g, 0.188 mmol), and K₂CO₃ (3.89 g, 28.1 mmol) in DME (180 ml) and water (50 ml) was refluxed under nitrogen for 14 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, washed successively with methanol, water, ethanol, ethyl acetate and heptane, then dissolved in dichloromethane and filtered through a short plug of silica gel. After evaporating the solvent, the crude product was triturated with ethanol and heptane to yield Compound C119 (4.0 g, 70%) as a white solid.

Synthesis of Compound C131 Synthesis of 2-(4-chlorophenyl)-4,6-bis(9,9-dimethyl-9H-fluoren-2-yl)-1,3,5-triazine

A solution of 2,4-dichloro-6-(4-chlorophenyl)-1,3,5-triazine (5 g, 19.19 mmol), (9,9-dimethyl-9H-fluoren-2-yl)boronic acid (9.14 g, 38.4 mmol), Pd(PPh₃)₄ (0.444 g, 0.384 mmol), and K₂CO₃ (7.96 g, 57.6 mmol) in DME (150 ml) and water (15 ml) was refluxed under nitrogen for 13 h. After cooling to room temperature (˜22° C.), the organic phase was isolated. After evaporating the solvent, the residue was purified by column chromatography on silica gel with heptane/DCM (4/1, v/v) as the eluent to yield 2-(4-chlorophenyl)-4,6-bis(9,9-dimethyl-9H-fluoren-2-yl)-1,3,5-triazine (5.43 g, 49.1%) as a white solid.

Synthesis of Compound C131

A solution of 2-(4-chlorophenyl)-4,6-bis(9,9-dimethyl-9H-fluoren-2-yl)-1,3,5-triazine (5.43 g, 9.42 mmol), (6-phenyldibenzo[b,d]thiophen-4-yl)boronic acid (2.87 g, 9.42 mmol), Pd₂(dba)₃ (0.129 g, 0.141 mmol), SPhos (0.116 g, 0.283 mmol), and K₃PO₄ (4.34 g, 18.85 mmol) in DME (200 ml) and water (25 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the organic phase was isolated and purified by column chromatography on silica gel with heptane/DCM (1/1, v/v) as the eluent to yield Compound C131 as a white solid.

Synthesis of Compound C134

A solution of (6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]thiophen-4-yl)boronic acid (2.25 g, 5.92 mmol), 2-chloro-4-(9,9-dimethyl-9H-fluoren-2-yl)-6-phenyl-1,3,5-triazine (2.4 g, 6.25 mmol), Pd(PPh₃)₄ (0.137 g, 0.118 mmol), and K₂CO₃ (2.453 g, 17.75 mmol) in DME (200 ml) and water (50 ml) was refluxed under nitrogen for 14 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, washed successively with methanol, water, ethanol, ethyl acetate and heptane, then dissolved in boiling toulene and filtered through a short plug of silica gel. After evaporating the solvent, the crude product was triturated with ethanol and heptane to yield Compound C134 (3.0 g, 75%)

Synthesis of Compound C139

A solution of 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]furan-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.41 g, 9.89 mmol), 2-(3-chlorophenyl)-4-(9,9-dimethyl-9H-fluoren-2-yl)-6-phenyl-1,3,5-triazine (4.25 g, 9.24 mmol), Pd₂(dba)₃ (0.211 g, 0.231 mmol), SPhos (0.379 g, 0.924 mmol), and K₃PO₄ (6.38 g, 27.7 mmol) in toluene (125 ml), DME (100 ml), and water (30 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the reaction mixture was extracted with toluene. After evaporating the solvent, the residue was purified by column chromatography on silica gel with heptane/toluene (4/1 to 1/1, v/v) as eluent to yield Compound C139 (4.1 g, 59.7%) as a white solid.

Synthesis of Compound C173 Synthesis of 2-(2,8-diphenyldibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

A solution of sec-butyllithium in cyclohexane (28.5 ml, 39.9 mmol) was added dropwise into a solution of 2,8-diphenyldibenzo[b,d]thiophene (7.45 g, 22.14 mmol) in anhydrous THF at −78° C. The reaction mixture was stirred at −78° C. for 2 h, while 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (7.21 g, 38.8 mmol) was added at a rate of 1 mL/min. The reaction mixture was gradually warmed to room temperature (˜22° C.) and stirred for 16 h before quenching with a 10% NH₄Cl aqueous solution. The resulting mixture was extracted with ethyl acetate. After evaporating the solvent, the residue was purified by column chromatography on silica gel with heptane/DCM (1/1, v/v) as the eluent and then recrystallized from heptane to yield 2-(2,8-diphenyldibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (5.5 g, 53.7%) as white crystals.

Synthesis of Compound 173

A solution of 2-(2,8-diphenyldibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.03 g, 6.55 mmol), 2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine (2.54 g, 6.55 mmol), Pd₂(dba)₃ (0.090 g, 0.098 mmol), SPhos (0.081 g, 0.197 mmol), and K₃PO₄ (3.02 g, 13.11 mmol) in DME (100 ml), toluene (100 ml), and water (10 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, washed successively with ethanol, water, ethanol and heptane, and then triturated with boiling toluene to yield Compound 173 (4.0 g, 95%) as a white solid.

Synthesis of Compound C185 Synthesis of 2-(6,8-diphenyldibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Sec-butyllithium in cyclohexane (38.2 ml, 53.5 mmol) was added dropwise into a solution of 2,4-diphenyldibenzo[b,d]thiophene (10 g, 29.7 mmol) in anhydrous THF at −78° C. The reaction mixture was stirred at −78° C. for 2 h, while 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (10.61 ml, 52.0 mmol) was added at a rate of 1 mL/min. The reaction mixture was gradually warmed to room temperature (˜22° C.) and stirred for 16 h before being quenched with a 10% NH₄Cl aqueous solution. The resulting mixture was extracted with ethyl acetate. After evaporating the solvent, the residue was purified by column chromatography on silica gel with heptane/DCM (4/1 to 0/1, v/v) as the eluent, then recrystallized from heptane to yield 2-(6,8-diphenyldibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (9.5 g, 69%) as white crystals.

Synthesis of Compound C185

A solution of 2-(6,8-diphenyldibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.29 g, 9.27 mmol), 2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine (3 g, 7.73 mmol), Pd(PPh₃)₄ (0.269 g, 0.232 mmol), and K₂CO₃ (2.14 g, 15.45 mmol) in DME (200 ml) and water (40.0 ml) was refluxed under nitrogen for 5 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, dissolved in boiling xylene, then filtered through a short plug of silica gel and recrystallized from xylene to yield Compound C185 (2.6 g, 52.3%) as a white solid.

Synthesis of Compound C251

A solution of 2-(4′-chloro-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine (3.0 g, 7.14 mmol), 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethylyl-1,3,2-dioxaborolane (3.53 g, 7.64 mmol), Pd₂(dba)₃ (0.196 g, 0.214 mmol), SPhos (0.40 g, 0.976 mmol), and K₃PO₄ (4.93 g, 21.43 mmol) in DME (80 ml), toluene (160 ml), and water (25 ml) was refluxed for 18 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, washed with water, then dissolved in boiling toluene and filtered through a short plug of silica gel, and recrystallized from toluene to yield Compound C251 (3.43 g, 67%) as a white solid.

Synthesis of Compound C254

A solution of 2-(6-([1,1′-biphenyl]-4-yl)dibenzo[b,d]thiophen-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.72 g, 5.89 mmol), 2-(3-bromophenyl)-4,6-bis(4-fluorophenyl)-1,3,5-triazine (2.5 g, 5.89 mmol), Pd₂(dba)₃ (0.081 g, 0.088 mmol), SPhos (0.073 g, 0.177 mmol), and K₃PO₄ (2.71 g, 11.79 mmol) in DME (200 ml) and water (50 ml) was refluxed under nitrogen for 18 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration and purified by column chromatography on silica gel with heptane/DCM (1/1, v/v) as the eluent and recrystallized from heptane to yield Compound C254 (2.5 g, 62%) as white crystals.

Synthesis of Compound D1

A solution of 2-(3-(dibenzo[b,d]thiophen-4-yl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.5 g, 9.06 mmol), 2-(4-chlorophenyl)-4,6-diphenyl-1,3,5-triazine (3.43 g, 9.97 mmol), Pd₂(dba)₃ (0.166 g, 0.181 mmol), SPhos (0.149 g, 0.362 mmol), and K₃PO₄ (5.77 g, 27.2 mmol) in DME (70 ml) and water (15 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the reaction mixture was diluted with water. The solid was collected by filtration, washed with methanol, dissolved in hot toluene and filtered through a short plug of silica gel. After evaporating the solvent, Compound D1 (4.20 g, 82%) recrystallized from toluene as a white solid.

Synthesis of Compound D2

A solution of 4-(4-chlorophenyl)dibenzo[b,d]thiophene (2.46 g, 8.35 mmol), 2,4-diphenyl-6-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,3,5-triazine (4.0 g, 9.19 mmol), Pd₂(dba)₃ (0.15 g, 0.17 mmol), SPhos (0.27 g, 0.67 mmol), and K₃PO₄ (2.89 g, 16.7 mmol) in DME (90 ml) and water (10 ml) was refluxed under nitrogen for 6 h. After cooling to room temperature (˜22° C.), the reaction mixture was diluted with water. The solid was collected by filtration, washed successively with water and methanol, re-dissolved in hot toluene, and filtered through a short plug of silica gel. After evaporating the solvent, Compound 248 (2.1 g, 50%) recrystallized from toluene as a white solid.

Synthesis of Compound F1

A solution of 2,4,6-tris(3-bromophenyl)-1,3,5-triazine (3 g, 5.49 mmol), [1,1′-biphenyl]-4-ylboronic acid (3.48 g, 17.58 mmol), Pd₂(dba)₃ (0.101 g, 0.110 mmol), SPhos (0.180 g, 0.440 mmol), and K₃PO₄ (2.332 g, 10.99 mmol) in toluene (54 ml) and water (6 ml) was refluxed under nitrogen for 12 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, the washed successively with water, methanol, and toluene. The crude product was purified by sublimation to yield Compound F1 (1.7 g, 40%) as a white solid.

Synthesis of Compound F2 Synthesis of 2-chloro-4,6-bis(3-chlorophenyl)-1,3,5-triazine

A solution of (3-chlorophenyl)magnesium bromide (50 ml, 50.0 mmol) was added dropwise into a solution of 2,4,6-trichloro-1,3,5-triazine (3.1 g, 16.7 mmol) in THF (50 ml) at 0° C. It was slowly warmed to room temperature (˜22° C.) and stirred for 2 h. The reaction mixture was diluted with toluene and poured into an aqueous solution of HCl (1M, 200 ml). The organic layer was isolated, washed with water, and then dried over Na₂SO₄. After evaporating the solvent, the residue was purified by column chromatography on silica gel to yield 2-chloro-4,6-bis(3-chlorophenyl)-1,3,5-triazine (2.1 g, 37%) as a pale yellow solid.

Synthesis of 2-([1,1′-biphenyl]-3-yl)-4,6-bis(3-chlorophenyl)-1,3,5-triazine

A solution of 2-chloro-4,6-bis(3-chlorophenyl)-1,3,5-triazine (3.6 g, 10.7 mmol), [1,1′-biphenyl]-3-ylboronic acid (3.2 g, 16.0 mmol), K₂CO₃ (4.4 g, 32.1 mmol) and Pd(PPh₃)₄ (0.62 g, 0.54 mmol) in DME (60 ml) and water (20 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the reaction mixture was filtered through a plug of silica gel. The filtrate was evaporated, and the residue was purified by column chromatography on silica gel with heptane/DCM (9/1 to 7/3, v/v) as the eluent and precipitation from DCM to methanol to give 2-([1,1′-biphenyl]-3-yl)-4,6-bis(3-chlorophenyl)-1,3,5-triazine (3.7 g, 76%) as a white solid.

Synthesis of Compound F2

A solution of 2-([1,1′-Biphenyl]-3-yl)-4,6-bis(3-chlorophenyl)-1,3,5-triazine (3.7 g, 8.1 mmol), [1,1′-biphenyl]-4-ylboronic acid (4.0 g, 20.4 mmol), Pd₂(dba)₃ (0.15 g, 0.16 mmol), SPhos (0.27 g, 0.65 mmol), and K₃PO₄ monohydrate (5.6 g, 24.4 mmol) in m-xylene (200 ml) and water (20 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the solid was collected by filtration and washed with water and toluene. The solid was then was dissolved in boiling o-xylene and filtered through a short plug of silica gel. After evaporating the solvent, Compound F2 (4.5 g, 80%) recrystallized from o-xylene as white solid.

Synthesis of Compound F3 Synthesis of 2-([1,1′-biphenyl]-4-yl)-4,6-bis(3-chlorophenyl)-1,3,5-triazine

A solution of 2-chloro-4,6-bis(3-chlorophenyl)-1,3,5-triazine (0.2 g, 0.59 mmol), [1,1′-biphenyl]-4-ylboronic acid (0.14 g, 0.71 mmol), K₂CO₃ (0.25 g, 1.78 mmol), and Pd(PPh₃)₄ (0.034 g, 0.030 mmol) in DME (21 ml) and water (7 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the reaction mixture was filtered through a plug of silica gel. The organic layer was isolated, washed with water, and then dried over Na₂SO₄. After evaporating the solvent, the crude product was purified by column chromatography on silica gel with heptane/DCM (9/1 to 7/3, v/v) as eluent to yield 2-([1,1′-biphenyl]-4-yl)-4,6-bis(3-chlorophenyl)-1,3,5-triazine (0.2 g, 74%) as a white solid.

Synthesis of Compound F3

A solution of 2-([1,1′-Biphenyl]-4-yl)-4,6-bis(3-chlorophenyl)-1,3,5-triazine (2.3 g, 5.1 mmol), [1,1′-biphenyl]-4-ylboronic acid (3.0 g, 15.2 mmol), Pd₂(dba)₃ (0.093 g, 0.10 mmol), SPhos (0.17 g, 0.41 mmol), and K₃PO₄ monohydrate (3.5 g, 15.2 mmol) in m-xylene (200 ml) and water (20 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the solid was collected by filtration and triturated with boiling o-xylene. The crude product was purified by sublimation to yield Compound F3 (2.1 g, 60%) as a white solid.

Synthesis of Compound F4

A solution of 2,4-dichloro-6-(9,9-dimethyl-9H-fluoren-2-yl)-1,3,5-triazine (2.2 g, 6.43 mmol), 2-([1,1′:4′,1″-terphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.75 g, 7.71 mmol), Pd(PPh₃)₄ (0.223 g, 0.193 mmol), and K₂CO₃ (2.67 g, 19.29 mmol) in DME (100 ml), toluene (100 ml), and water (20 ml) was refluxed under nitrogen for 16 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration, then washed successively with water and toluene to yield Compound F4 (1.7 g, 36%) as a white solid.

Synthesis of Compound F7 Synthesis of 2-chloro-4-(dibenzo[b,d]thiophen-4-yl)-6-phenyl-1,3,5-triazine

A solution of dibenzo[b,d]thiophen-4-ylboronic acid (5.0 g, 21.92 mmol), 2,4-dichloro-6-phenyl-1,3,5-triazine (12.39 g, 54.8 mmol), Pd(PPh₃)₄ (1.267 g, 1.096 mmol), and K₂CO₃ (9.09 g, 65.8 mmol) in THF (Ratio: 10.0, Volume: 199 ml) and water (Ratio: 1.000, Volume: 19.93 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (22° C.), the reaction solution was filtered through a short plug of silica gel. The crude product was purified by column chromatography on silica gel and sublimation to yield 2-chloro-4-(dibenzo[b,d]thiophen-4-yl)-6-phenyl-1,3,5-triazine (7.1 g, 72%) as a yellow solid.

Synthesis of Compound F7

A solution of 2-([1,1′:4′,1″-terphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.359 g, 6.62 mmol), 2-chloro-4-(dibenzo[b,d]thiophen-4-yl)-6-phenyl-1,3,5-triazine (2.25 g, 6.02 mmol), Pd(PPh₃)₄ (0.348 g, 0.301 mmol), and K₂CO₃ (2.495 g, 18.05 mmol) in DME (Ratio: 10.0, Volume: 54.7 ml) and Water (Ratio: 1.000, Volume: 5.47 ml) was refluxed under nitrogen overnight (˜12 hours). After cooling to room temperature (˜22° C.), the reaction mixture was diluted with water and THF. The solid was collected by filtration, washed successively with water, THF and ethanol, triturated successively with hot ethanol, DCM and toluene, and then sublimed to yield Compound F7 (3.24 g, 77%) as a white solid.

Synthesis of Compound F13 Synthesis of 2,4-dichloro-6-(9,9-dimethyl-9H-fluoren-2-yl)-1,3,5-triazine

A solution of 2-bromo-9,9-dimethyl-9H-fluorene (12.0 g, 43.9 mmol) in THF (100 ml) was added dropwise into a suspension of Mg (1.6 g, 65.9 mmol) in THF (50 ml) activated with iodine at 60° C. under nitrogen. After addition, the reaction mixture was refluxed for 3 h before transferring it into a solution of 2,4,6-trichloro-1,3,5-triazine (8.10 g, 43.9 mmol) in THF (50 ml) at 0° C. The reaction mixture was then allowed to warm to room temperature (˜22° C.) and stirred overnight (˜12 hours) before quenching with an aqueous HCl solution. The resulting mixture was extracted with EtOAc. The combined organic extracts were dried over Na₂SO₄. After evaporating the solvent, the residue was purified by column chromatography on silica gel with heptane/EtOAc (9/1, v/v) as the eluent to yield 2,4-dichloro-6-(9,9-dimethyl-9H-fluoren-2-yl)-1,3,5-triazine (8.0 g, 53%) as a white solid.

Synthesis of 2-([1,1′:4′,1″-terphenyl]-3-yl)-4-chloro-6-(9,9-dimethyl-9H-fluoren-2-yl)-1,3,5-triazine

A solution of 2-([1,1′:4′,1″-terphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.00 g, 11.23 mmol), 2,4-dichloro-6-(9,9-dimethyl-9H-fluoren-2-yl)-1,3,5-triazine (10.76 g, 31.4 mmol), Pd(PPh₃)₄ (0.259 g, 0.225 mmol), and K₂CO₃ (4.66 g, 33.7 mmol) in DME (150 ml) and water (50 ml) was refluxed under nitrogen for 18 h. After cooling to room temperature (˜22° C.), the reaction mixture was diluted with water, then extracted with EtOAc and the organic extracts were dried over Na₂SO₄. After evaporating the solvent, the residue was purified by column chromatography on silica gel with heptane/EtOAc (4/1, v/v) as the eluent to yield 2-([1,1′: 4′,1″-terphenyl]-3-yl)-4-chloro-6-(9,9-dimethyl-9H-fluoren-2-yl)-1,3,5-triazine (4.5 g, 8.39 mmol, 74.8% yield) as a white solid.

Synthesis of Compound F13

A solution of 2-([1,1′:4′,1″-terphenyl]-3-yl)-4-chloro-6-(9,9-dimethyl-9H-fluoren-2-yl)-1,3,5-triazine (2.7 g, 5.04 mmol), dibenzo[b,d]thiophen-4-ylboronic acid (1.72 g, 7.56 mmol), Pd(PPh₃)₄ (0.116 g, 0.101 mmol), and K₂CO₃ (2.1 g, 15.11 mmol) in toluene (200 ml), DME (300 ml), and water (50 ml) was refluxed under nitrogen for 14 h. After cooling to room temperature (˜22° C.), the solid was collected by filtration and washed successively with water, methanol, EtOAc, and heptane. The crude product was dissolved in boiling toluene and filtered through a short plug of silica gel. After evaporating the solvent, the Compound F13 (16.5 g, 48%) precipitated as a white solid.

Device Examples

Application in OLED.

All devices were fabricated by high vacuum (˜10⁷ Torr) thermal evaporation. The anode electrode was 80 nm of indium tin oxide (ITO). The cathode electrode consisted of 1 nm of LiF followed by 100 nm of A1. All devices were encapsulated with a glass lid sealed with an epoxy resin in a nitrogen glove box (<1 ppm of H₂O and O₂) immediately after fabrication, and a moisture getter was incorporated inside the package.

Device Examples—Set 1

A first set of device examples have organic stacks consisting of, sequentially, from the ITO surface, 10 nm of LG101 (from LG Chem) as the hole injection layer (HIL), 45 nm of 4,4′-bis[N-(1-naphthyl)-N-phenylaminolbiphenyl (NPD) as the hole-transport layer (HTL), and 30 nm of Compound E8 with 20 wt % of inventive compound (Compound C65) or comparative compound (CC-1) and 10 wt % of emitter GD as the emissive layer (EML). On top of the EML, 50 nm of Compound C65 or CC-1 was deposited as the hole blocking layer (HBL), followed by 40 nm oftris(8-hydroxyquinolinato)aluminum (Alq₃) as the electron-transport layer (ETL). The structures of the compounds used are shown below.

Table D1, below, is a summary of the device data, voltage (V), external efficiency (EQE) and power efficiency (PE), recorded at 9000 nits for the Device Example 1.

TABLE D1 EQE Device EML HBL Color V (V) (%) PE (lm/W) Device C-1 E8: CC-1: GD CC-1 Green 8.1 14.5 20.5 Device 1 E8: C65: GD C65 Green 7.6 15.1 22.5

The data in Table D1 shows that Device 1 using inventive compound Compound C65 as the co-host and HBL achieves higher efficiency at a lower driving voltage than Device C-1 using comparative compound CC-1 as the co-host and HBL.

Device Examples—Set 2

A second set of device examples have the same structure as that in Device Example 1 except that an inventive Compound C101 or a comparative compound CC-2 doped with 15% of GD is used as a two-component EML. The chemical structures of the inventive and comparative compounds used are presented below.

Table D2, below, is a summary of the relative device data recorded at 9000 nits for the Device Example 2. Device lifetime LT97 is defined as the time it takes for devices to decay to 97% of their original luminance under a constant current density with an initial luminance of 9000 nits, and the values are normalized to that of Device C-2.

TABLE D2 EQE PE Device EML HBL Color V (V) (%) (lm/W) LT97 Device C-2 CC-2: GD CC-2 Green 7.5 14.7 22 100 Device 2 C101: GD C101 Green 7.6 14.7 23 130

The data in Table D2 shows that Device 2 using inventive compound Compound C101 as the host and HBL achieves higher efficiency and longer lifetime than Device C-2 using comparative compound CC-2 as the host and HBL.

Device Examples—Set 3

A third set of device examples have the same structure as that in Device Example 1. The chemical structures of the inventive and comparative compounds used are presented below.

Table D3, below, is a summary of the relative device data recorded at 1000 nits for the Device Examples 3. Device lifetime LT95 defined as the time it takes for devices to decay to 95% of their original luminance under a constant current density with an initial luminance of 1000 nits, was calculated, with an acceleration factor of 1.8, from the values measured at a current density of 50 mA/cm², and normalized to that of Device C-3.

TABLE D3 Device EML HBL Color LT95 Device C-3 E8:CC-3:GD CC-3 Green 100 Device 3 E8:A5:GD A5 Green 694 Device 4 E8:A116:GD A116 Green 529 Device 5 E8:C74:GD C74 Green 537

The data in Table D3 show that, using as cohost with E8 in EML and as EBL, inventive compounds having substitutions on dibenzothiophene or bridging phenyl demonstrate longer lifetime than comparative compound that does not have these substitutions.

Device Examples—Set 4

A fourth set of devices have the same structure as that in Device Example 2. The chemical structures of the inventive and comparative compounds used are presented

below.

Table D4, below, is a summary of the relative device data recorded at 1000 nits for the Device Example 4. Device lifetime LT95 was normalized to that of Device C-4.

TABLE D4 Device EML HBL Color LT95 Device C-4 CC-4:GD CC-4 Green 100 Device C-5 CC-5:GD CC-5 Green 3 Device C-6 CC-6:GD CC-6 Green 3 Device C-7 CC-7:GD CC-7 Green 147 Device C-8 CC-8:GD CC-8 Green 93 Device C-9 CC-9:GD CC-9 Green 62 Device C-10 CC-10:GD CC-10 Green 88 Device 6 A10:GD A10 Green 899 Device 7 A11:GD A11 Green 602 Device 8 A14:GD A14 Green 1029 Device 9 A17:GD A17 Green 848 Device 10 A32:GD A32 Green 969 Device 11 A38:GD A38 Green 721 Device 12 A47:GD A47 Green 859 Device 13 A110:GD A110 Green 902 Device 14 A113:GD A113 Green 1248 Device 15 B3:GD B3 Green 1136 Device 16 B7:GD B7 Green 849 Device 17 C23GD C23 Green 1466 Device 18 C29:GD C29 Green 344 Device 19 C47:GD C47 Green 915 Device 20 C56:GD C56 Green 287 Device 21 C71:GD C71 Green 181 Device 22 C83:GD C83 Green 444 Device 23 C110:GD C110 Green 477 Device 24 C119:GD C119 Green 285 Device 25 C134:GD C134 Green 192 Device 26 C140:GD C140 Green 824 Device 27 C173:GD C173 Green 760 Device 28 C251:GD C251 Green 1830 Device 29 F4:GD F4 Green 314 Device 30 F13:GD F13 Green 223

The data in Table D4 show that OLED devices using inventive compounds as hosts and HBL have longer lifetime than that using comparative compounds.

Device Examples—Set 5

A fifth set of devices have the same structure as that in Device Example 1. The chemical structures of the inventive and comparative compounds used are presented below.

Table D5, below, is a summary of the relative device data recorded at 9000 nits for the Device Example 5. Device lifetime LT97 is defined as the time it takes for devices to decay to 97% of their original luminance under a constant current density with an initial luminance of 9000 nits, and the values are normalized to that of Device C-11.

TABLE D5 V EQE PE Device EML HBL Color (V) (%) (lm/W) LT97 Device E8: CC-11 Green 8.1 13.9 19.4 100 C-11 CC-11: GD Device 31 E8: D2: GD D2 Green 7.7 14.8 21.8 123

The data in Table D5 shows that Device 31 using inventive compound Compound D2 as the host and HBL achieves higher efficiency and longer lifetime than Device C-11 using comparative compound CC-11 as the host and HBL.

The device data in Tables D1 through D5 together show that the inventive compounds having unique chemical structures are superior to comparative compounds when they are used as hosts or co-host and EBL in OLEDs. It is well accepted that OLED device performance is highly dependent on the materials properties, which are attributable to materials chemical structure.

Premixture Examples

The compatibility of selected h- and e-hosts was evaluated by compositional analysis of films fabricated by single-source co-evapoaration of the premixture of these two components. A first set of potential premixtures of selected h- and e-hosts are presented in Table PM1.

TABLE PM1 Potential premixtures comprising selected h- and e-hosts Premixtures h-hosts e-hosts PM-A1 Compound E1 Compound C1 PM-A2 Compound E2 Compound C2 PM-A3 Compound E5 Compound C65 PM-A4 Compound E8 Compound C74 PM-A5 Compound E11 Compound C74 PM-A6 Compound E17 Compound C74 PM-A7 Compound E8 CC-1 PM-A8 Compound E8 Compound A5 PM-A9 Compound E8 Compound C17 PM-A10 Compound E17 Compound A5 PM-A11 Compound E25 CC-1 PM-A12 Compound E26 Compound C74 PM-A13 Compound E26 Compound C248 PM-A14 Compound E28 Compound C74 PM-A15 Compound E29 Compound C74 PM-A16 Compound E30 Compound C74

Premixture Example—Set 1

For premixture PM-A4, Compound E8 and Compound C74 were provided at a weight ratio of 7:3, then they were physically mixed, grinded and loaded into an evaporation source. The premixed compositions were thermally co-evaporated at a rate of 2 Å/s in a vacuum chamber under a pressure less than 10⁻⁷ Torr, and deposited onto glass substrates. The substrates were replaced continuously after deposition of 500 Å of film without stopping the deposition and cooling the source. The compositions of films were analyzed by high-performance liquid chromatography (HPLC) and the results are shown in Table 2.

TABLE PM2 HPLC composition (%) of sequentially deposited films from premixture (PM-A4) comprising Compound E8 and Compound C74 with weight ratio 7:3. (HPLC Conditions C18, 100 45 min, Detected wavelength 254 nm) (Due to different absorption coefficients, the HPLC composition may or may not agree with the weight ratio.) Films Compound E8 Compound C74 Plate1 69.5 30.5 Plate2 68.4 31.6 Plate3 68.2 31.8 Plate4 68.2 31.8 Plate5 68.4 31.6 Plate6 69.3 30.7 Plate7 70.6 29.4 Plate8 71.7 28.3 Plate9 73.0 27.0

As shown in Table PM2, the composition of the components Compound E8 and Compound C74 did not change significantly from plate 1 through plate 9. The minor fluctuations in the concentrations do not reveal any trend and can be explained by the accuracy of HPLC analysis. Normally, the change of the concentration before and after depositions within 5% throughout the process is considered to be good and useful for commercial OLED application.

Premixture Example—Set 2

For premixture PM-A12, Compound E26 and Compound C74 were provided at a weight ratio of 3:2, then they were physically mixed, grinded, and loaded into an evaporation source. The premixed compositions were thermally co-evaporated at a rate of 2 Å/s in a vacuum chamber under a pressure less than 10⁻⁷ Torr, and deposited onto glass substrates. The substrates were replaced continuously after deposition of 500 Å of film without stopping the deposition and cooling the source. The compositions of films were analyzed by high-performance liquid chromatography (HPLC) and the results are shown in Table PM3.

TABLE PM3 HPLC composition (%) of sequentially deposited films from premixture (PM-A12) comprising Compound E26 and Compound C74 with weight ratio 3:2. (HPLC Conditions C18, 100 45 min, Detected wavelength 254 nm) (Due to different absorption coefficients, the HPLC composition may or may not agree with the weight ratio.) Films Compound E26 Compound C74 Plate1 67.1 32.9 Plate2 67.3 32.7 Plate3 68.4 31.6 Plate4 69.6 30.4 Plate5 70.8 29.2 Plate6 71.9 28.1 Plate7 72.9 27.1 Plate8 73.9 26.1

Again, the results of plates 1 to 8 show only minor variations and would be considered to be good and useful for commercial OLED application.

Premixture Example—Set 3

For premixture PM-A16, Compound E30 and Compound C74 were provided at a weight ratio of 1:1, then they were physically mixed, grinded and loaded into an evaporation source. The premixed compositions were thermally co-evaporated at a rate of 2 Å/s in a vacuum chamber under a pressure less than 10⁻⁷ Torr, and deposited onto glass substrates. The substrates were replaced continuously after deposition of 500 Å of film without stopping the deposition and cooling the source. The compositions of films were analyzed by high-performance liquid chromatography (HPLC) and the results are shown in Table PM4.

TABLE PM4 HPLC composition (%) of sequentially deposited films from premixture (PM-A16) comprising Compound E30 and Compound C74 with weight ratio 1:1. (HPLC Conditions C18, 100 45 min, Detected wavelength 254 nm) (Due to different absorption coefficients, the HPLC composition may or may not agree with the weight ratio.) Films Compound E30 Compound C74 Plate1 52.3 47.7 Plate2 51.6 48.4 Plate3 52.1 47.9 Plate4 52.9 47.1 Plate5 53.9 46.1 Plate6 54.6 45.4 Plate7 51.8 48.2

The data in Tables PM2, PM3 and PM4 show that the ratio of the two components in premixtures PM-A4, PM-A12 and PM-A16 does not change significantly over a continuous single-source coevaporation. The minor fluctuations in the concentrations do not reveal any trend and can be explained by the accuracy of HPLC analysis. Normally, the change of the concentration before and after depositions within 5% throughout the process is considered to be good and useful for commercial OLED application. These experiments conclude that PM-A4, PM-A12 and PM-A16 are stable premixtures for coevaporation. The coevaporation stability of these premixtures is believed to tracable to the unique chemical structures associated with these two classes of materials.

A second set of potential premixtures of selected h- and e-hosts are presented in Table PM5.

TABLE PM5 Potential premixtures comprising selected h- and e-hosts Premixtures h-hosts e-hosts PM-B1 Compound G1 Compound F9 PM-B2 Compound G2 Compound F10 PM-B3 Compound G8 Compound F13 PM-B4 Compound G9 Compound F13 PM-B5 Compound G26 Compound F5

Example 1

For premixture PM-B3, Compound G8 and Compound F13 were provided at a weight ratio of 9:1, then they were physically mixed, grinded and loaded into an evaporation source. The premixed compositions were thermally co-evaporated at a rate of 2 Å/s in a vacuum chamber under a pressure less than 10⁻⁷ Torr, and deposited onto glass substrates. The substrates were replaced continuously after deposition of 500 Å of film without stopping the deposition or cooling the source. The deposition was stopped upon material depletion. The compositions of films were analyzed by high-performance liquid chromatography (HPLC) and the results are shown in Table PM6.

TABLE PM6 Table PM6: HPLC composition (%) of sequentially deposited films from premixture (PM-B3) comprising Compound G8 and Compound F13 with weight ratio 9:1. (HPLC Conditions C18, 100 45 min, Detection wavelength 254 nm) (Due to different absorption coefficients, the HPLC composition may or may not agree with the weight ratio.) Films Compound G8 Compound F13 Plate1 95.9 4.1 Plate2 96.0 4.0 Plate3 96.5 3.5 Plate4 96.8 3.2

The composition of the components Compound G8 and Compound F13 did not change significantly from plate 1 through plate 4. The minor fluctuations in the concentrations do not reveal any trend and can be explained by the accuracy of HPLC analysis. Normally, the change of the concentration before and after depositions within 5% throughout the process is considered to be good and useful for commercial OLED application. These results demonstrate that PM3 is a stable premixtures for coevaporation. The coevaporation stability of this premixture is believed to be tracable to the unique chemical structures associated with these two classes of materials.

It is understood that the various embodiments described herein are by way of example only, and are not intended to limit the scope of the invention. For example, many of the materials and structures described herein may be substituted with other materials and structures without deviating from the spirit of the invention. The present invention as claimed may therefore include variations from the particular examples and preferred embodiments described herein, as will be apparent to one of skill in the art. It is understood that various theories as to why the invention works are not intended to be limiting. 

1. A composition of materials comprising a first compound, wherein the first compound has a formula:

wherein G¹ is selected from the group consisting of dibenzofuran, dibenzothiophene, dibenzoselenophene, and fluorene; wherein L¹ is selected from the group consisting of phenyl, biphenyl, terphenyl, pyridine, pyrimidine, and combinations thereof; wherein L² and L³ are each independently selected from the group consisting of a direct bond, phenyl, biphenyl, terphenyl, pyridine, pyrimidine, and combinations thereof; wherein G⁴ is selected from the group consisting of phenyl, biphenyl, terphenyl, naphthalene, phenanthrene, pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, phenanthroline, and combinations thereof; wherein G², G³, and G⁵ are each independently selected from the group consisting of phenyl, biphenyl, terphenyl, fluorene, naphthalene, phenanthrene, pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, phenanthroline, aza-fluorene, and combinations thereof; wherein G², G³, G⁴, and G⁵ are each optionally further substituted with one or more unfused substituents selected from the group consisting of deuterium, alkyl, alkoxyl, cycloalkyl, cycloalkoxyl, halogen, nitro, nitrile, silyl, phenyl, biphenyl, terphenyl, pyridine, and combinations thereof; wherein m is an integer from 0 to 7, wherein n is an integer from 1 to 4; and wherein, when m or n is larger than 1, each G⁴ or G⁵ can be same or different.
 2. The composition of claim 1, wherein G⁴ has the structure selected from the group consisting of:


3. The composition of claim 1, wherein G¹ has the structure selected from the group consisting of:

wherein X is selected from a group consisting of O, S and Se; wherein R^(B1) and R^(B2) are independently selected from a group consisting of hydrogen, deuterium, alkyl, cycloalkyl, alkoxyl, aryl, heteraryl, halogen, and combinations thereof; and wherein R^(B1) and R^(B2) are optionally joined to form a ring.
 4. The composition of claim 1, wherein L¹ is selected from the group consisting of:


5. The composition of claim 1, wherein G², G³ and G⁵ are independently selected from the group consisting of:

wherein R^(B1) and R^(B2) are independently selected from a group consisting of hydrogen, deuterium, alkyl, cycloalkyl, alkoxyl, aryl, heteraryl, halogen, and combinations thereof; and wherein R^(B1) and R^(B2) are optionally joined to form a ring.
 6. The composition of claim 1, wherein at least one of G², G³, G⁴ and G⁵ is substituted with at least one fluorine atom.
 7. The composition of claim 1, wherein the first compound has the formula:

wherein X is selected from a group consisting of O, S and Se.
 8. The composition of claim 1, wherein the first compound is selected from the group consisting of:


9. The composition of claim 1, wherein the composition comprises a second compound; wherein the second compound has the formula II:

wherein Ar¹ is selected from the group consisting of triphenylene, and aza-triphenylene; wherein Ar² is selected from the group consisting of a direct bond, phenyl, biphenyl, terphenyl, naphthalene, pyridine, dibenzofuran, dibenzothiophene, dibenzoselenophene, aza-dibenzofuran, aza-dibenzothiophene, aza-dibenzoselenophene, and combinations thereof; wherein Ar³ is selected from the group consisting of benzene, biphenyl, terphenyl, naphthalene, pyridine, dibenzofuran, dibenzothiophene, dibenzoselenophene, aza-dibenzofuran, aza-dibenzothiophene, aza-dibenzoselenophene, carbazole, aza-carbazole, and combinations thereof; and wherein Ar¹, Ar² and Ar³ are each, independently, optionally further substituted with one or more substitutions selected from the group consisting of deuterium, halogen, alkyl, aryl, heteroaryl, and combinations thereof.
 10. The composition of claim 9, wherein the second compound is selected from the group consisting of

wherein X is selected from the group consisting of O, S and Se; wherein R¹ and R⁴ each independently represents mono, di, or tri, substitution, or no substitution; wherein R², R³, R⁵, and R⁶ each independently represents mono, di, tri, or tetra substitution, or no substitution; and wherein R¹ to R⁶ are each independently selected from the group consisting of hydrogen, deuterium, benzene, biphenyl, terphenyl, naphthalene, fluorene, triphenylene, phenanthrene, dibenzofuran, dibenzothiophene, carbazole and combinations thereof.
 11. The composition of claim 9, wherein the second compound is selected from the group consisting of


12. A composition comprising a mixture of a first compound and a second compound selected from the group consisting of:


13. The composition of claim 1, wherein the composition comprises a second compound; wherein the second compound is a phosphorescent emissive Ir complex having at least one substituent selected from the group consisting of alkyl, cycloalkyl, partially or fully deuterated variants thereof; partially or fully fluorinated variants thereof; and combinations thereof.
 14. A first device comprising a first organic light emitting device, the first organic light emitting device comprising: an anode; a cathode; and an organic layer, disposed between the anode and the cathode, comprising A composition of materials comprising a first compound, wherein the first compound has a formula:

wherein G¹ is selected from the group consisting of dibenzofuran, dibenzothiophene, dibenzoselenophene, and fluorene; wherein L¹ is selected from the group consisting of phenyl, biphenyl, terphenyl, pyridine, pyrimidine, and combinations thereof; wherein L² and L³ are each independently selected from the group consisting of a direct bond, phenyl, biphenyl, terphenyl, pyridine, pyrimidine, and combinations thereof; wherein G⁴ is selected from the group consisting of phenyl, biphenyl, terphenyl, naphthalene, phenanthrene, pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, phenanthroline, and combinations thereof; wherein G², G³, and G⁵ are each independently selected from the group consisting of phenyl, biphenyl, terphenyl, fluorene, naphthalene, phenanthrene, pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, phenanthroline, aza-fluorene, and combinations thereof; wherein G², G³, G⁴, and G⁵ are each optionally further substituted with one or more unfused substituents selected from the group consisting of deuterium, alkyl, alkoxyl, cycloalkyl, cycloalkoxyl, halogen, nitro, nitrile, silyl, phenyl, biphenyl, terphenyl, pyridine, and combinations thereof; wherein m is an integer from 0 to 7, wherein n is an integer from 1 to 4; and wherein, when m or n is larger than 1, each G⁴ or G⁵ can be same or different.
 15. The first device of claim 14, wherein the organic layer is an emissive layer and the composition is a host.
 16. The first device of claim 14, wherein the organic layer further comprises a phosphorescent emissive dopant; wherein the phosphorescent emissive dopant is a transition metal complex having at least one ligand or part of the ligand if the ligand is more than bidentate selected from the group consisting of:

wherein each X¹ to X¹³ are independently selected from the group consisting of carbon and nitrogen; wherein X is selected from the group consisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO₂, CR′R″, SiR′R″, and GeR′R″; wherein R′ and R″ are optionally fused or joined to form a ring; wherein each R_(a), R_(b), R_(c), and R_(d) may represent from mono substitution to the possible maximum number of substitution, or no substitution; wherein R′, R″, R_(a), R_(b), R_(c), and R_(d) are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and wherein any two adjacent substitutents of R_(a), R_(b), R_(c), and R_(d) are optionally fused or joined to form a ring or form a multidentate ligand.
 17. The first device of claim 16, wherein at least one of R_(a), R_(b), R_(c), and R_(d) is selected from the group consisting of alkyl, cycloalkyl, partially or fully deuterated variants thereof; partially or fully fluorinated variants thereof; and combinations thereof.
 18. The first device of claim 14, wherein the organic layer is a blocking layer and the composition is a blocking material in the organic layer, or the organic layer is an electron transporting layer and the composition is an electron transporting material in the organic layer.
 19. The first device of claim 14, wherein the first device is selected from the group consisting of a consumer product, an electronic component module, an organic light-emitting device, and a lighting panel.
 20. (canceled) 